Alternator Shootout at Idle (136 vs 160 vs 250 amp)

[@TheRealMikeWilly]

One thing I learned while working in auto parts, an alternator's amperage rating is given @ 2000 rpm. So when it comes to idle speed power production, all goes out the window, 160 amp alternator A will more than likely produce something different than 160 amp alternator B. Currently running the durango 160 amp alternator in my XJ and my volt meter hardly moves down off 14v even with my sub thumpin and my stereo blasting.

[@jordantrujillo293]

That’s impressive, my XJ will drop from 14-12v with just the AC fan coming on.

[@TheRealMikeWilly]

@@jordantrujillo293 the only way I can get my volt meter to hit 12v is by winching my Jeep up a long steep incline with 12-18" tall steps after blowing up my transfer case on the trail and getting no output to either axle, all the while runnin my instant pot to heat up dinner. 5000w power inverter + instant pot = everybody inviting you on every wheelin trip and offering to bring the food if you'll just bring the way to get it hot 🤣🤣

[@chrclmnky]

This video demo is absolutely genius. Gives me the courage to swap out my crappy mini van's alt and slap a higher amperage to keep up with the car audio demands.

[@chrclmnky]

@therockkkkher not yet but i am about to. Will post the video soon my channel. I will be using alternator from a Nissan Caravan NV350 150A alternator or from a Mitsubishi Pajero 110A alts. I already bought these two and will fabricate steel mountings. Really soon my channel.

[@1.4tmechanicscruze61]

what you need my good sir is a big v3/v4 kit its a bigger AWG depending on what accessories you have like for an example i have aftermarket accessories like 2 mini light bars 2 600w amps 1200w alpine subs wheel well multi color led lights upgraded msd coil pack for wider spark plug gaps (.035) the vehicle manufacturers are the cheapest bastards and with that being said they run thin gauge wires from your alternator to battery and even battery ground as well as engine ground so simple solution is before you replace your alternator buy a big v3 kit for YOUR TYPE of vehicle install the kit DONT replace factory wire just put your new kit wire typically 0-4 AWG over your existing factory wire this will save you time and money by not having to buy another alternator because more then likely the factory AWG isnt letting the alternator produce the electric capacity its really capable of 🤟🏼🤟🏼👌

[@squirtmph]

@@1.4tmechanicscruze61 Exellente point of view, allowed me to ask the questions & equipment Should I do Only 3 big as you had suggested nor alternator & 3 Big. I'm planing to hire a professional car Audio to do the job. 2018 CHEVROLET SONIC LT HATCHBACK 4 DR 1.4L I4 F DOHC 16V Amperage Output : 100 Amp ******"Equipment******" JL Audio VX600/1i Amplifier VX1000/1i Monoblock Class D Amplifier DRC-205 Digital Remote Control for JLid JL Audio 12W7AE-3Anniversary Edition W7 Series 12" 3-ohm subwoofer Focal PS 165 FXEPerformance Series 6-1/2" Maximum power: 160W Focal PC165F Flax 6.5” Maximum power: 140W Focal Elite Utopia M Tweeters Maximum Power: 200W Thanks 😊👍☕

[@jefferyjulio4915]

I realize I'm pretty off topic but do anyone know a good website to watch newly released series online?

[@mylesfrancisco814]

@Jeffery Julio lately I have been using flixzone. You can find it on google =)

[@kanepua4796]

Good info. Some things need to perform at idle, like A/C when stuck in traffic.

[@blasekaauamo756]

Nice video. You could also upgrade your charging and ground wires to help with the load. I am into car audio and upgrading the charging and ground wires make a huge difference as well.

[@martinbuilt]

Thanks for the tips!

[@Sip28]

The wires should be thicker right?

[@jpowens2253]

@joshsmith9 no, but it allows more power to be utilized more easily. It's like the difference of trying to breathe though a straw verses a paper towel roll.

[@jeremyfancher]

@@martinbuilt yes do whats called big 3 for car audio systems you can not get 250 amps current thru the prob 8 ga stock charge wire run at least 2 gauge from alt to batt and 2 ga grounds also or go 1/0 gauge even better i have stock 90 cheaper puttin 14.7 idle then when turn everything on i get to 13.3 i have all wire 0 gauge make sure its pure or ofc copper do not get cheap cca

[@jeremyfancher]

what kind of battery are you running make sure its atleast agm

[@stoichiometry147]

Martin: Thanks for these videos, you've saved me a lot of time in R&D on my 4.7's. I'm glad my 49mm pulley calculations were correct. Seems the 160 has much better windings. I'll be employing your combo (AIRRAM/ATI, 49MM and 160). Keep these coming

[@martinbuilt]

Right on

[@pallskrewee3091]

Great video. As noted by another viewer, the slower rpm speed will have a dramatic effect on the alternator. Of course you proved that by installing a smaller diameter pulley. Also, the vehicles computer may also have an effect, the type of battery, & the age of the battery itself may have an effect. I had a 2015 Chevy cargo van that would cause voltage drops from the stock alternator. I called the dealership, asking if this was normal, & they said yes. I further inquired as to why, and it was explained to me that it was part of the fuel economy system. Certain times when I was going up a incline/ hill, the computer would cut off the alternator in order to reduce HP drawn on the engine, which helps with fuel economy. This would also happen with the air conditioner in the summer time. Also noted by another viewer was to perform the big three upgrade. Especially if you are installing a higher current output alternator. Your stock electrical wiring is generally rated for the current demands from the electrical system. Car manufacturers only give you what you need. Nothing more.

[@Bigv57thG]

U are a life saver Been trying to find info on this but nobody did a video like this keep up the great work brother

[@martinbuilt]

Thanks, will do! Appreciate it!

[@adambatchelder4121]

Good comparison. Your under drive crank is really hurting the output. Keep in mind that the alternators cooling fans are also turning slower, more heat

[@bitzombie1]

This video addresses the questions in my mind as far as aftermarket alternators and pulley size effect at different RPM ranges. Informative video without a ton of extra gibberish.

[@JohnAdams-lg3mh]

Great work Martin, I was certain the 250 amp would be more than enough to level out the voltage, Glad you posted the video. Keep’em coming!

[@martinbuilt]

Glad you enjoyed it

[@jkstdstang]

It wasn’t a real 250 amp alternator. Amazon junk.

[@1ftintheflames]

You may also try this with a multimeter on the alternator post. Ive found that any digital guages plugged into the obd2 port usually display lower than what the actual voltage output of the alternator is. Id check at the alt post, battery post and the input post of the junction box. Scan tools also display lower than actual voltage. Also anytime ive done a h.o. alternator i replace the lead from the alt to battery and to the junction box with heavier guage ofc wire like 2 gauge. That always seems to improve things. 8 and 10 gauge with fusible links can only allow so much current at a time. Great vid keep em comin.

[@jth1987leb]

Thanks. I need to get a new alternator. Now I know to get the 160amp and the smaller pulley. Great video

[@dizzydezel9899]

You should do a big 3 upgrade on you charging system wiring! With a larger alternator your bottle necking the power flow of the high out alternator!

[@1.4tmechanicscruze61]

exactly what i suggested that could save people a lot of money by not having to buy another alternator they could just install a big 3 kit a lot of people don't know about it and end buy a bigger voltage alternator and have the same problem basically your factory wire is not producing the electricity that your alternator can really put out DONT UPGRADE ALTERNATOR UPGRADE AWG lol

[@SoldierNoodles]

@@1.4tmechanicscruze61 where can I buy it

[@alexanderk6512]

thats not the issue here, its the low alternator speed. the only fix is reducing pully size. just because you have a H/O output alternator doesnt mean you will get higher voltage at low RPM. H/O alternators actually need higher speeds to reach their regulated voltage.

[@mighty9100]

@@alexanderk6512 but even if you reduce pully size and get more amps, the factory wire cannot support the increased amps. Upgrade the wire size. 1/0

[@SacredHeart0520]

​@mighty9100 nit true. It's just depends on what your stick wiring is. Mine is 4 Guage . From factory

[@SouthernKillafornia]

Great video and Mopar to boot. I killed my battery this past weekend running headlights, fuel pump and fans at idle waiting to get into a car show. You gave me plenty of great info.

[@martinbuilt]

Thank you, I'm glad you liked it and found it helpful. Hope you did well at the car show.

[@richhancock3110]

I think that underdrive pulley really hurts your charging from your alternators wonder if the 250 amp would do allot better with correct speed compared to the 160amp

[@weskirkland5850]

What I found out that pissed me off was it seems buying high amp alternators generally charge less at idle speed then your stock alternator. they charge more when wound up but idle speed is critical if you drive in any kind of daily traffic.

[@TerryManitoba]

This was just the video I needed to determine if my alternator was right for my van conversion. Thanks for that... I had a 30 amp bc/dc charger to charge my 220 amp lithium house batteries, I recently upgraded by connection in parallel an additional 40 amp bc/dc charger (both RedArc). Before turning on the chargers the at idle output was 13.8 v. With just the 30 amp bc/dc on the volts when to 13.6. With both chargers on volts when to 13.4 & is charging at 72.4 amps. I am assuming the alternator is sized appropriately? Right???

[@ghssanalkhwyter9754]

Many thanks for your simple and very good explanation and alternators tests

[@gmax341]

Glad I ran into this video. Had the same issue when upgrading to a higher amp alternator. The idle performance was just horrible. With a full load it started to dip in the 10s with voltage. Accessories would sound slower and the all the lights on dash would flicker a bit if already illuminated (but was fine higher RPM). This was after I have done my big 3 upgrade. Luckily I still had my previous alternator and decided to slap that back in. 14 Volts across the board sometimes hitting 13. Returned the High amp alt and got my funds back. Not sure what my current alternator puts out as I had a shop replace my older one but just wanted a bit more amp headroom for the equipment I am running.

[@Sip28]

So you think 250 amp isn’t good?

[@gmax341]

@@Sip28 didn’t say that. I Probably had a defective alternator or wrong pulley size. Not to long ago I purchased a 200amp powermaster, so far so good! 96 E150 5.8l V8

[@Sip28]

@@gmax341 I had power master too but isn’t the idle amperage 130?

[@gmax341]

@@Sip28 yes that’s correct. My idle at warm is around 500-600rpm

[@Sip28]

@@gmax341 130 too low for me. I need idle to be be at least 180amp

[@JUKE179r]

Thanks for this video. I've got a 2001 Land Rover Discovery 2 (L318) with a 4.0L Thor engine and a stock 120A alternator. A 2001 Land Rover Range Rover (P38) with a slightly bigger 4.6L Thor engine with a stock 150A alternator. Many Discovery 2 owners have stated that the Range Rover 150A alternator is adaptable to our Discovery 2s. Thanks for your experiments showing the differences. Cheers from a 'Murican in the UK!

[@DarkLinkAD]

Nice Buick

[@klwflorida5438]

Hey Martin thanks for your help earlier. I fixed my AC in an old jeep I bought. 2002 Overland. The compressor works fine! Just needed 134 a. Did the dye no leaks. Might be a small one at schrader valve. That all I saw. I was trying to find the low pressure sensor to jump it over but after recharge it works fine. Hubs and brakes r next! I will catch some more of your videos for that. Boy you r such a huge help. I have air tools too. Glad you are here!!

[@martinbuilt]

Glad it helped

[@oscarcrespo9365]

This is completely new in my knowledge. Thank you Sr. You are the man Sr.

[@martinbuilt]

Glad to help

[@letitrest4662]

Thanks Martin. This is actually something I've been curious about, because I'm considering doing a cargo van conversion, with electrical system.

[@martinbuilt]

I'm glad you liked it and found it helpful 👍 😊

[@larryfine4498]

I saw elsewhere on YT that high amp (aftermarket) alternators get their amperage from rewiring the windings in the stator from series to parallel (or vice versa). High rpm performance is improved at the cost of low rpm performance.

[@herlemaggard69]

Depends what company, i just bought a 320a from autotech engineering that puts out 170ish at idle(650rpm)

[@reubenj.cogburn8546]

Where was the AMPERAGE reading? Did I miss the critical unit of measurement ( as in the video title)?

[@MrLongshot762]

From my understanding, alternator output is stated at 3600rpm. Idle will be dramatically lower hence the need for a battery. A battery is your fuel tank. Your alternator will replenish your battery while driving and do what it can at idle. A 160 alternator will output only 65-70 amps at idle with the stock pulley. Electric cooling fans can pull 30-40 amps alone. Really need that battery capacity to be available as much as an alternator ready to replenish it.

[@airborne63]

Thanks. I have both a 130 amp and a 200 amp alternator for my Ford.....and neither put out enough at idle....in drive at a stoplight, to maintain the battery with 'winter' stuff on, like heater blower, headlights and defogger..... Will try the smaller pully.

[@martinbuilt]

Sounds good, it worked out good for me.

[@crunkwun]

Alot of things need to be considered here. The 160a with small puller may keep higher voltage under load but the 250a will supply more amperage under load(depending what rpm that 250a is specified). If you're wanting more voltage depending if your alt is internally regulated then a couple diodes will fix that(15v+) or if you're externally regulated then you may have to look at an external regulator with the 250a alt.

[@martinbuilt]

The thing is by adding diodes or a resistor and trying to boost the voltage will not work at idle because the the voltage regulator is already telling the alternator I'm looking for 13.8 or whatever voltage if the alternator can't produce it at that RPM changing a voltage regulator or adding diodes or resistors will not make any difference in my case.

[@crunkwun]

@@martinbuilt so I'm guessing your alt is externally regulated.. you would need an adjustable external regulator then and yes.. you can adjust voltage to whatever you need cold start.

[@toneseeker4968]

Oh Brother...thank you so much for this video! You just saved me a lot of money. I'm not a mechanic in the least, but I find myself in the market for a new alternator, knowing absolutely zilch about them. The video I watched here on youtube just before watching yours told me outright to buy the biggest alternator I can afford and not to worry about it, that it has no ill affect on my vehicle whatsoever. And, that way I would be prepared for any added electrical add ons in the future. I was shocked to see these results of your. It was like watching Goldilocks' Garage....not too cold, not too hot, but just right! Liked and subscribed...

[@UltraCon79]

Great video. I just put a chrysler 320 Amp 200 at idle JS Alternator on my 2.4L 2016 Jeep Renegade Trailhawk. I had a 160A stock but now my MPG has gone up from 32highway to 38 to 41 and my voltage is 14.3 at my cigar outlet with AC on max and fan running.

[@barryodog]

Lower voltage means more amps, that's why alt was so hot. putting out amps to get back to voltage set point

[@randyrawdingii5135]

Interesting about the idle speed... Getting ready to put an '04 Sequoia alternator in my '06 IS250. Thanks for the great vid! God bless...

[@martinbuilt]

Thank you. I'm glad you liked it and found it helpful. Good luck with your upgrade.

[@jaysonmartinez2830]

Good information! I wouldn't have thought the 160 would out preform the 250

[@trevortrevortsr2]

I think the 160 is star wound and the 250 delta

[@rodom303]

Thanks for the video I was just thinking about changing my alternator

[@martinbuilt]

Glad I could help

[@Bigv57thG]

Me too I got 7k watts im trying to feed.

[@Bigv57thG]

martinbuilt can I get a link on the 250

[@martinbuilt]

@@Bigv57thG and here is another link Eagle High Fits 250 Amp Alternator Dodge Dakota V6 3.7L 226cid 2004-2006 Dakota V8 4.7L 285cid 2005-2006 amzn.to/3dBWW7E

[@davef.566]

First put bigger charge wire on alt 4awg or bigger

[@demmerdesign6356]

I swear I am not some shill for the company, but you have to check out Mechman alternators. I have a 6.0 Powestroke (with fully upgraded wiring for + and -) truck that absolutely eats alternators due to the plowing and really low idle / 3.5k maximum RPMs. Those things actually deliver real idle output and they even come rated and pretested at Idle and running speeds. I've installed them on every truck I own barring one junker van. Your video absolutely made me feel better about spending $500 on a 320 amp alt from them. Plus no need to run a smaller pully unless you wanted to.

[@givemethemusicd]

I would have been interested in Amp draw measurements at idle under maximum load.

[@jlwz71]

I bypassed the pcm voltage regulator with one from a early 80's dodge. It is adjustable voltage on the back, I set mine to 14.5 and it only dipped a couple of tenths here and there. You have to put a resistor on the pcm wire to fool the pcm so you won't get a code p044. I also have the 136 amp alt. Just an idea.

[@martinbuilt]

One of those things I might do one of these days.

[@mfslyphantom8811]

Thank you for that, I’ve been upgrading these on different vehicles for years and never knew a 160 would ever outperform a 250 all things being equal (idle rpm). Never do the builders mention any of that useful info.

[@martinbuilt]

No problem 👍glad I could help.

[@Sip28]

Right wonder why is it the opposite?

[@David-mu1wz]

video very helpful. I now realize i fried my alternator driving city speeds with all accesories on plus a 1500w amp.

[@michalukasz1660]

The voltage depends on few factors not just pulley size and alternator size. The alternator amperage, the battery size, the battery quality class, and the load, the resistance of the circuit. These 3-5 factors. I remember that for a 3.2-4.3 liter mercedes ML, 1998, a battery size of 100amp hours or 725CCA and an alternator sized 115 AMP, was factory reccomended back then. Of course now the alternator sizes put by manufacturers are greater. Say a 540CCA stock battery in GM cars with 1.6 liter engines is matched with a 100 to 120 AMP or 150 AMP alternators with the option for the buyer to put a max size of 680CCA battery. Also the outside temperature affects the batteries ability to hold energy, whcih is less during winter and better during summer. Thus a battery might need a warming cover. With an AC fan running at max speed-3rd or 4th speed in GM cars, during hot summer the battery voltage in european Opel Zafira 1.6 can go down to 12.7 volts with stock alternator of 120AMPS and 680 CCA battery.

[@WanderingRobotStudio]

Doing the Lord's work.

[@Tombstone226]

tech tip I have learnt it's not just voltage you look at but also amperage as well

[@ahmedkamalalkamali6929]

Check the idle solnoid activity, check battery cells, clean all ground n earth sockets n contactors upgrade all grounds to higher gage wire , finally check or replace voltage regulator n the belt

[@Benny-dv7xm]

I want to upgrade because I need to the car is under-engineered and only one acessory hurts engine preformance at idle. It seems like you are indicating that the voltage is more critical than the amps when you have enough amps as in the situation of(?) 160 amps and 250 amps. Are you concerned about the voltage with regard to the ignition system because the accesories are running and the voltage holds at or over battery voltage with the accesories on. Or, does this start that suggested process of too much draw on the system, the battery kicks in to give out power, but then a low voltage never allows the battery to get fully recharged and creates a draw for power perhaps greater if the plate material starts to degrade. Or will some components not function at 12v or less especially considering that was at idle.

[@martinbuilt]

My concern was that the battery will not be fully charged and that the cooling fan would not run at a sufficient rpm to cool the engine.

[@irishjoe9195]

4:13 Nice Fart Martin, oh yes the “blend” doors I will start using that one as well

[@DEInTheGarage]

How did I miss this one back in May?? Sure wish I had seen this before basically re-doing this research. I landed on the 160 Durango alternator for my 01 snow plow WJ with an electric winch

[@martinbuilt]

Hello, I like the 160 it has been working well for me. Hopefully, that will be enough for your snowplow. 🤔

[@georgemorales4264]

@@martinbuilt hey do you know where to find the smaller pulley?? Thanks, loved the video!

[@martinbuilt]

Here is a 49mm pulley amzn.to/3HY7huA Thank you. I'm glad you liked it 👍

[@steven6692]

Thanks for the video. According a few wj owners the pcm quits regulating the voltage at some point...some of them even junked their wj's for not knowing what to do...but the few that kept the wj just installed a voltage regulator fixed at 14.3...but it has an adjustment screw on the back to increase or decrease...i bougth one from alternatormen...end of problem..cheers!

[@martinbuilt]

I will look into that, thank you!

[@JohnSmith-ot9sc]

Huh, that's interesting. I thought for sure the 250 would have given you the best results. Great vid as always 👍

[@martinbuilt]

Thank you! Cheers!

[@larryfine4498]

It's the way they wire the high amp alternators to get that amperage. Performs better at higher rpms, but at a cost to low rpm oerformance.

[@HokieD1993]

Ya, my ZJ has electric fan, stereo and the stock alternator can't handle it when I have accessories on. Thanks for the video. I'll think about a 160 and a 49mm for sure

[@martinbuilt]

let me know how it works out.

[@mrmotofy]

FYI 13.5v is normal float voltage for a fully charged lead battery. Charging voltage is generally 14.4-14.8v. There's frequently a voltage drop in all that electrical equipment. Check it at the battery or alternator. I can almost guarantee it's a higher voltage. Normally minimal driving is at idle...while it's interesting useful info...it's not a very realistic factor for most.

[@martinbuilt]

A good alternator should put out between 13.5-14.4 volts. If the charge gets above 14.5 volts, your battery will overheat and boil

[@travisc3571]

Nice video Martin. This is Scott’s brother from Louisiana. I hear all kinds of martinbuilt stories. 👍👍

[@douglasking6714]

Do different vehicles have different voltages every car I checked was at or around 14.7 while running.and if your going with bigger alternator do the big 3 upgrade

[@larryfine4498]

More is not better in the case of batteries and auto charging systems. Voltages above 14.4 will diminish battery life.

[@mrmotofy]

Nope...he was starting with an under drive pulley. Which spins everything slower

[@obuadhachain]

0:34 - I own a 2011 Dodge Grand Caravan - My Alt failed 3 Saturdays ago - I have been without a car ever since - a week later my Antifreeze line busted somewhere - no antifreeze - Over heating going on. "A few moments Later" - my dashboard lights began to flicker - and I'm NOT 100% certain my Power Steering isn't about to blow. Ok - ... I need help. Alts are 5 Gs. 5 Gs I don't have. There's a Toyota Tundra (perhaps it's still available) that is 8 Gs. 8 Gs I don't have. But it is a good vehicle. I need to get back to work. I would appreciate ANY prayers. I am in the Austin area.

[@garydwyer641]

Thanks Martin that was very interesting as are all your videos I don't own a jeep but applicable to others. Keep up the good work and Hi from Australia.

[@jasonbrown467]

would be curious to see the actual current load on the system while turning those items on one at a time. i always thought 14.4v was what the alternator puts out, that is what all of mine are anyways. then the based on the load and the gauge of the wires versus the alternator's max current is at any given rpm will determine voltage drop. if your cables from the alt to the battery and ground are too small for the load the voltage will drop, and waste energy in the form of heat on the conductors.

[@stevenhensley5060]

I guess I think 4 things (great video BTW): your belt drive system is underdrive to start, none of the alternators perform well at 600RPM (luckily I don't drive at 600 RPM), and the 136 AMP was working hard under any circumstance, and I agree, the 160amp was best balance between $ and performance, although I am curious about reliability and life.

[@deantk4214]

Great video Martin! I’d love to see a repair video on the blend doors, or one on how to repair the heated seats🤙🏼

[@donsgotmoney]

Excellent comparison, Ive got an older Chevy with a 5.7, my alt output with my a/c and electric fan on it pulls it down to 11.9 volts. Now I just gotta find at minimum a 130 amp alt, ive found a 200 amp, but have always thought that was to much anyways,

[@hectorvega2163]

Awesome demo and general info on those alternator tests. Thanks 😊

[@martinbuilt]

Thank you I'm glad you liked it and found it helpful. 😊

[@JuanGarcia-nl6ut]

I have been working for long time on alternator the hair pins has double stator plus very small pulley you can have good results

[@EINKODM]

So nice and helpful video. Where can I get the monitoring system shown in your video? Thx so much ❤

[@bjornahh87]

but there is a lot of other things to consider too, like on the 90's mitshubichi's they use the grounds at the body's chassis and not the battery negative termninal, and doing so that car struggeled with the same as you did, with way to low charging voltage, so remember to have - negative going directly from battery to engine body and then to the car's body for the rest, and btw how does your alternators regulate the voltage? Is it built inside the alternators or is there a sensing wire going from your positive battery to your cars dashboard "no charge/battery lamp" and then back into the alternators sensing port, is there a separate ground cable for the internals of the alternator? like those marine alternators that needs separate grounds so your boat engine doesn't corrode to hell.., there is a lot to consider, how would it be if you wired the one pin to field to max and made the sensing wire shorter, woulld not the alternator put out more amperage so the voltage would go up too, even though you got low voltage with the smallest alternator, does not mean that the voltage you showed us, is the contstant voltage across the battery, then you need an ampere clamp and separate voltage meter over the battery, and btw where does that tuning device you got, where does it measure the voltage, directly from the battery or via the ecu? btw I love the video and work you have done to get a point out to people..

[@chicanobluesaz4191]

Voltage is not what you want to be checking as long as your in an acceptable charging range. You need to have an amp meter to see the real winner.

[@jimbobdobbs1597]

This is what i was wondering also-.and no mention of brand or if was a hairpin type design or the standard

[@mikeanderson3565]

Amazon alternators are junk anything under the 370 dollar range is garbage. Your biggest mistake your alternator wire is not 1/0 to the battery there goes your voltage the big 3 has to be done. That jeep if it's got 2 awg I be shocked probably 4 awg. Good for 130 amps and that's still under sized. 0 gauge is 1/0 not 1 awg go get some welding wire short positive to battery off alternator 1/0 to two grounds a 1/0 to frame and a good ground to motor. Get your self a custom electric alternator from Ohio 250 amp stock pulley. A real good agm battery and you will be at 14.5 volts. I run 5000 watts on a microphone that's transmit power and much bigger stuff then 3 of your jeeps can run. I'm on 3 500 dollar batteries.

[@BVN-TEXAS]

If you are dipping below 12 at idle it means your alternator can’t keep up with the load and is letting it sag down. Checking voltage is a quiz and easy way to see if the alternator is keeping up. Amp clamp is when you have reason to deeper diagnostics.

[@chicanobluesaz4191]

@@BVN-TEXAS Nice re-hash! Keep on spreading great knowledge 👍

[@charliedee9276]

I replaced my the one in my 04 when it went bad with one from a Durango, I believe it is a 160.

[@martinbuilt]

Yeah many of the Durango's have 160 amp alternators that's where I got the one I used in this test from.

[@seadoo_detroit]

Great video.....question...i have a wj jeep...yellow top optima....im running alit of led lights on roof. Im up grading my 1500 watt inverter to 3000 to accomidate coffee maker....should i stuo up the alternator,or just grab another battery and tie that in with isolator

[@martinbuilt]

I would 1st try upgrading the alternator to 160 amp and then also also do the big 3 upgrade grade on the battery cables.

[@joesam8113]

Great demo video, I want to know by adding up more amp from the alternator will it effects the components Like Ac , high beam , signal lights and Radio. And other electronic parts in the car tq

[@martinbuilt]

Thank you, the alternator will not put out more amperage just because it has a higher amperage alternator it is only gonna put out what is required of the electrical system.

[@rfmonkey4942]

the same spec can be found in an alternative alternator if you can find the model you want from mechman guys "its a VELEO 11358" unit that comes stock in bmw e70 e.t.c or the bigger unit that comes in the M50d the small unit does 230amp idle and 370 at rev haven't tested the big unit's peak new equipment need to be built for that seems like over 400 amps (make my load catch fire) these unit are used in other German cars to with all different types of mounts keep in mind the oem BMW version uses LIN bus for control (BMW x5 alternators are cheap & everywhere !) not E53 versions ! must be newer e70 & onwards

[@Halfbreed-pg2zg]

Great video!! I understand alternators a lot better after viewing this. Thanks 😊

[@martinbuilt]

Thank you I appreciate that. I'm glad you liked it and found it helpful. Thank you for watching. 🙂

[@turnerstech]

The overdrive pulley listed in description doesn’t work with my stock alt on 04 wj it also doesn’t fit the Durango 160 upgrade both denso alts it’s rubbing both alternator’s .. bummer love the vid tho !

[@martinbuilt]

Did that pulley not come with a spacer to be installed between the alternator and pulley?

[@MaytagManstan]

Good video. Have you tried upgrading the big four?

[@ivanvujadinovic9905]

Also, is there a link for the 49mm pulley? Or any details on groves, bore size etc?

[@martinbuilt]

Let him know that I sent you and make sure he supplies a washer as well, you may need it. www.ebay.com/itm/49MM-1-9-Alternator-OVERDRIVE-6-GROOVE-PULLEY/253996371394?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

[@michaelsinger1031]

@@martinbuilt Thanks for the link, subbed I will try to get some more of my products up for you guys

[@huf67]

I had the same problems with my blend doors !!! Changed everything out and still had the same issues !! I thought I knew what that sound was... Had to laugh when you confirmed it. 😂🤣

[@martinbuilt]

yeah the previous owner had the blend doors replaced and they still do it, I've heard it is a Grand Cherokee thing. I just live with it.

[@timeless6964]

I Noticed that as You put items on, your RPM also kicked Down!!

[@billbird3833]

Some alternators dont seems to charge untill a certain rpm. Say 1200 rpm, glad you tried the smaller pulley

[@DarkLinkAD]

Mr Electron

[@symy3386]

Very scientifically done. Great job and very helpful information. Thank you for the work you put into your videos.

[@martinbuilt]

Thank you!

[@cactusjackdanels9829]

Great video… I accidentally came across your channel and I have subscribed… Good stuff…Very informative

[@martinbuilt]

Thank you I appreciate that. And thank you for watching and subscribing.

[@georgesrisomsak9650]

I just rebuilt my 100 amp OEM Toyota hairpin, with better OEM parts from a Dodge Durango to better cope with the 800+ amp draw it receives in my car. Larger 12 - 50 amp diode rectifier plate vs 6- 35 amp, 1.8 ohm rotor, and re- configured the stator to do 240 Amps. It is an improvement from the 2.2 ohm rotor, and 6 diode plates factory. Still not happy with idle output, I bought another new denso 160a stator, tore it down again(solder joints @ the rectifier plates were a bitch) and after the new stock stator, I have a very stable 155+ amps at cold dead idle with a small pulley. Actually pretty good for a small case. I'll upload a video later this next week, I have a genuine denso regulator that has a higher base voltage setpoint(14.5 vs 13.6v) with temperature compensation on the way. When that's installed, I'll make a video of it clamped at full temp. I plan on a large case DC power unit(XP270 - 220a hot idle 270+ at speed. It'll take a while to get here. For now, and playing with this small case, learning about the difference in parts, and how easy it is to make an OEM home built - high output alternator yourself, its actually incredibly easy. I even devised a way to have variable voltage control on the fly from inside with a variable 6k ohm resistor. I really should make a tutorial on the next build. It's fun doing it yourself, I even painted the case when it was apart, even looks like a professional aftermarket unit. I'll get something real good posted here soon. No reason why others can't build a very high quality unit of their own as well. Thanks for posting, it confirms my exact experience, and upon research and finding this video, I know after all the work again tearing it apart, it was ultimately the right choice for down low power. You da man!

[@kingofkisses2008]

Thanks for sharing. But electrically speaking, the 250A alternator should be capable of handling the load more than the 160A one, as the voltage drop will be less on the 250A one than the 160 one. This should be the case unless the 250A alternator has some problem with its voltage regulator.

[@BK-gc1jm]

nice video. I have a Ram Eco diesel. I need more amps to charge my batteries for my inverter when the power is out. we cannot run generators at night. Which size pulley do you recommend. I show 13 volts at idle on my dash. would like it a little higher.

[@martinbuilt]

sounds like the voltage is just slightly low. I don't know what size pulley you have now but I would just go with one that is a few millimeters smaller.

[@Pittsburgh-412]

I'm pretty sure that crystler vehicles need a voltage regulator to boost the voltage up

[@davidortega6359]

I ordered the 49mm pulley with the Amazon link that you list and what I got was a 6 groove pulley with a lip (~3mm) on the backside that the black one shown in your video doesn't have - did they send me the wrong pulley or do I have to have that lip machined off?? The pulley that I pulled off the stock alternator does not have that lip. Please advise. Thanks, in advance - love your videos!

[@martinbuilt]

I'm not sure about the lip on the pulley if it needs one or not I would install it and if the pulley lines up with all the other ones once the belt is installed you should be good.

[@davidortega6359]

So, I tried to install the Powermaster 115, as you suggested, but while it slips over the alternator shaft, with the lip on the back it doesn't let the pulley sit far enough down on the shaft to allow enough threads to grab the nut! This is because the thickness of the stock pulley from the flat backside to the 'inside' front lip is only ~7mm. This allows the stock pulley, once installed, to leave plenty of exposed thread to accommodate the washer and nut to secure the pulley to the alternator. For the Powermaster 115 the distance from the back lip to the inside front where the washer and nut seat is ~15mm. When the Powermaster 115 is installed, your left with 1 or 2 threads to grab the nut! And, because the threads on the nut are recessed a bit there is no chance to to grab the threads on the shaft! It would be awesome if you could take pictures (front/back/side/inside) of the 49mm pulley that you used in your video to help clarify things. Thanks, in advance

[@PC-ex9sr]

Hi Martin. I`ve problem with my JGC 2000 4.7 PT. I have a problem with my alternator or it's not an alternator. It all happened suddenly. I came, I turned off the engine and now, when I try to start the engine, it works badly, the lights on the board are all on, it works like on 4 cylinders and there is no power. When I disconnect the plug from the alternator everything is fine. If I turn it on again, it is bad. The alternator is fixed - I picked up yesterday. The charging current is 14.4V

[@martinbuilt]

Sounds like it's all working great now. 14.4V is perfect.

[@PC-ex9sr]

@@martinbuilt Charging is ok but all time engine works badly. All time When I disconnect the plug from the alternator everything is fine. If I turn it on again, ( this plug ) it is bad. I don’t know what to do yet!

[@PC-ex9sr]

@@martinbuilt Sorry to ask again but I `ve new problem witj my WJ. Jeep still in the garage. The alternator shows over 16V - multimeter - and 0V on the dashboard clock. Alternator plug connected - engine breaks - multimeter shows over 16V - no power, disconnected plug works perfectly - of cource without voltage. Electricity only from the battery. Is it the voltage regulator in the PCM or some wires or sensor or ground? Help.

[@martinbuilt]

@@PC-ex9sr Yes the voltage regulator is in the PCM

[@dominickmonaco1237]

Man I wish you lived in South Florida. Gotta change out one of my lifters, got a slight tick going on. Just changed the valve covers last weekend.

[@peterlakers1]

This great video But you should have tested it on the road to see if any voltage keeping up or drop.🤔 With everything on?

[@martinbuilt]

Next time

[@JoshSmith-wo7zw]

You can start by upgrading all your battery cables to 1/0 OFC will allow you to pull a little more amperage out of your stock alternator. If it still can't maintain 13 volts then I would give mechman a call and have them build you one that will easily handle what you're looking to do.

[@anthonycook8737]

Have you tried a stand alone, variable voltage regulator to bypass the PCM voltage regulator? I'd like to see how that affects voltage/ alt performance at idle. Set the thing at 14.4v and then rerun these tests.

[@martinbuilt]

I haven't, I will one of these days but, I personally don't think it will make a difference. The ECM's voltage regulator is not keeping the alternator from putting out the minimum voltage required to charge the battery.

[@anthonycook8737]

@@martinbuilt no... but it has the voltage caped at 13.7 volts. If you start with a voltage closer to normal charging voltage (14.4v as in most all other manufacturers), voltage drop will be lessened even when using the same accessories. The more you tax the alternator, the more rapidly it falls off. It's basically a logarithmic function.

[@TheCthtoNicfLy]

Wow that was really cool bro. Hell that's a lot of time for us.

[@martinbuilt]

Thank you i'm glad you like it.

[@CMOTC]

Reserve matters as well... your battery has makes a huge difference from a lead acid 20ah battery vs 80ah agm vs a 48ah lithium bank. This test was good but like working out only the left leg on leg days. As I finished typing this I realized this video is 4 years old. 🤣 Either way it was still informative 👍

[@joeygee11]

I use your videos for my 99 Jeep GC Limited 4x4. These are great!

[@martinbuilt]

Glad you like them!

[@404Sleepy]

Hey, i Have a question im hoping you could answer pertaining to my alternator and audio system

[@faisalalmudharreb9475]

Amazing and educated video. I need your advice. I have Toyota Land Cruiser 100 series 4.7 L V8. I installed 12000lb electrical winch. Looking for high output Alternator. What do you suggest?

[@martinbuilt]

Mechman or DC Power Engineering

[@Scrambler85]

The temperature of the alternators should have been measured at idle. Running high amps at idle has burned up a lot of alternators or caused vehicle fires. Victron charging systems has a video on their channel showing the excessive heat at idle on the alternators at idle.

[@matt7467daddy]

My problem is i have a sound system that pulls a lot your opinion would the 250 with the 49 do me best . My systems a 1olm in series set of 12in subs at 1800 watts but peak is 2500 and I have light bar and interior lights led .have 1000cold crank battery much larger than stock for this but still heavily dim lights when subs hit ......help please great video by the way good in site

[@201231]

You can start by getting another battery and a shumacher charger and top off every few days. Then when you upgrade your sounds you can get the 250 or greater, my 3k amp recommends a 250 amp fuse. The problem I have is volt drop ,so I turned the Gain down and set my knob on the epic center (bass restoration ) to a quarter or half (max) depending on song. I ordered a 250a high rpm mechman alt which should be here tomorrow, I will update you when I install it

[@judgedredd8876]

My stock Chevy 5.3l with 145A generator shows 14.4 to 14.7V at idle with no extra loads.

[@robertpeters9438]

Use an external regulator and pull sensing voltage at the battery instead of at the alternator!!! You might need a shielded wire for the sensing voltage!

[@cbronsonda13th37]

Do you guys know about autotechengineering they have alternators for imports like the 10th gen Honda Civic

[@allensnook7760]

Hey martin ,nice comparitive testing.iam owner of 2002 grand limited and it has the quad 2 /44 diffs in it.because it reguires friction modifers in it.what gear oil do you top off urs with.i really dont feel like a trip to dealership to get it done.plus with covid shutdown they might not even be open.dont have an issue just want to refresh fluids.!!all help appreciated.glad to see ur still putting out content.keep gearing snookie pa.

[@robertpeters9438]

Is there a 2 speed clutch from AC units you could use to increase alternator speed at idle?

[@rener5399]

What about the 4 L in-line six in my 2000 Jeep grand Cherokee? What’s the best alternator for me to run in that thing and I’m having an overheating problem the fan won’t kick on. It’s a relatively new radiator and fan. What’s up with that?

[@Entertainmentinc1]

id say the 160 with the 49mm pully outperformed the 250apm alternator, regardless of how they built the 250amp alt i think they shoulda made it to hold 13 v at all engine rpms, i was shocked it didnt even perform good with a 49mm at idle. i mean lets say im trying to show off my big sub to a friend, im not gonna rev my engine to 4000rpm for that 250 amp alt to work, just doesnt make sense, i hope the manufacturer change their way of thinking and make their alt put out 13-14v and 250amp around 700rpm, that would be perfect

[@SuperReznative]

... low rpm, high load /output=overhearing.. high rpm, adds cooling (fan internal fan. Notice how hot the alternator when he was holding it..

[@1.4tmechanicscruze61]

what you need my good sir is a big v3/v4 kit its a bigger AWG depending on what accessories you have like for an example i have aftermarket accessories like 2 mini light bars 2 600w amps 1200w alpine subs wheel well multi color led lights upgraded msd coil pack for wider spark plug gaps (.035) the vehicle manufacturers are the cheapest bastards and with that being said they run thin gauge wires from your alternator to battery and even battery ground as well as engine ground so simple solution is before you replace your alternator buy a big v3 kit for YOUR TYPE of vehicle install the kit DONT replace factory wire just put your new kit wire typically 0-4 AWG over your existing factory wire this will save you time and money by not having to buy another alternator because more then likely the factory AWG isnt letting the alternator produce the electric capacity its really capable of 🤟🏼🤟🏼👌