The Big Shunt Wire Guide - Prevent Electrical Meltdown In Your Classic Mopar With This Easy Fix

On today's episode, I install a charge bypass wire (or "shunt wire") in a 1970 Dodge Challenger to help protect the new wiring harness I just installed. I have used the same procedure in my 1968 Dodge Charger, my 1963 Plymouth Valiant, and countless other cars. In fact, this is a useful technique for just about any classic car with an ammeter, or amp gauge - especially in cases where various electrical components have been upgraded, or accessories have been added. It's quick, it's easy, it's cheap, and the only downside is a less accurate ammeter. This is one improvement that every owner of a classic Chrysler product should consider.

[@barrycuda3769]

Very well explained, not ammeterish at all .

[@harmorehorń]

Not the video we wanted... the video we NEEDED

[@iamnoone.]

JAMIE. been doing the same thing since 77 after letting the smoke out of the wiring on a 71 barracuda

[@idaholineman5788]

Saving countless mopar wiring harnesses for years to come!!

[@Don67Satellite]

I love that your explanation for "why" is clear & concise for anyone to understand. About 3 years ago I did the "underhood bypass" with the wire from the ALT to the starter relay stud. Also, I bypassed the bulkhead connections for the RED/BLACK charge wires, which is like the fleet bypass/shunt. And lastly, I removed the connections from the ammeter bolted them together, and protected/taped them up. Installed a voltmeter. This was after a 100A alternator upgrade and the Packard terminals had already had some melting going on. Has been great ever since despite not having much for electrical loads other than a Progression Ignition distributor.

[@JustMoparJoe]

Well shunt the bed! Nice one. I’m saving this to share with people. I get this question about 5 times a year.

[@BlindBatG34]

Jamie, you sir are the Mopar Care Bear we all need. Thanks buddy.

[@madbrax5184]

I bypassed the ammeter entirely on my 73 Charger and carefully replaced it with a voltmeter. I managed to keep the original look of the rally dash. I adjusted the voltmeter for a reading of 12.8 to be the center of the original ammeter so it mostly behaves like original. It's a little more active than the original and maybe a little twitchy during turn signal use but it does correctly represent the charging/battery state of the system.

[@craighansen7594]

Good idea using the ammeter to read voltage.

[@brokentoolgarage]

Nice! I bypass my amp gauges and replace with a voltmeter every time. Oh, and bump up the charge wire.

[@DigitalRelay]

Great video! I bought a non-running 74 Scamp six months ago. A previous owner had bypassed the ammeter, but the electrical system was a general mess. I added a shunt wire, cleaned 99% of all connectors, replaced burned up wiring, replaced the ammeter with a volt meter, added relays for headlights, and rebuilt the alternator after it failed from the brushes falling apart. Good as new!. For now.

[@johnkendrick7304]

You absolutely hit the nail in the head regarding the electrical systems for mopar's. I had these cars when they weren't classics in they have always had that very weakness that you're speaking about

[@guylr7390]

Me too. Been there,did that on my A bodies

[@pcbullets8726]

This is definitely some useful info that even a novice like myself can understand. Thanks!

[@richardlabell6505]

Thanks Jamie, I am going to an aluminum radiator with electric fan on my 71 Duster, I had to upgrade my alternator so this will be put into place when doing the install. By the way, you're a great teacher and this weekend warrior muscle car guy really appreciates you!!

[@DeadDodgeGarage]

Happy to do it! Thanks!

[@TrinityDestroyer]

Last summer, I had an issue on my 1970 Dodge Dart where my alternator wasn’t charging my battery, though it would keep the car running if it was already running. I do have an electric pump and fans, and I replaced my alternator, battery, voltage regulator, checked my wiring, added relays, and nothing I did could get the alternator to charge the battery. Then I watched one of your previous videos about MOPAR electrical systems, and added a shunt wire per your recommendation. That solved the problem, and she’s been running perfectly ever since. I do plan on replacing all the wiring once I can afford to do so, as 50 years of different owners have kinda made the cars wiring a mess, and do plan to go back to mostly original wiring, with only additions for the fuel pump and fans, and I do plan on installing a digital gauge cluster.

[@DeadDodgeGarage]

Nice! I’ve run into that a couple times. Well fixed.

[@barto6577]

One thing I found helpful on Dodge trucks with the 67 amp and larger alternators, is to clean and solder the bolts to the back of the gauge. There is only a weak crimp on a steel to copper connection there. Repeated heat cycles and the vibration of a truck WILL loosen those over time. That's why most older Dodge truck clusters are melted and/or charred there.

[@skydogwonderpup6952]

Excellent video! Thanks 65 Polara project - The dead Dodge in my garage

[@Dan-ee2hp]

Finally 😂😂 I’ve been waiting for this video for a year now ❤

[@blown_bacon9487]

I like the “mad electrical” site for the wiring upgrade. I also complain like a baby on insulated crimp connections. Ever since I was a teen in the 80’s when my speaker wires fell off continuously

[@blown_bacon9487]

Drummed in my head on the mad site from moparts days

[@DeadDodgeGarage]

Yeah! I’ve seen that before.

[@jeffreyschweiger7960]

There is a service bulliten about upgrading the wireing. I installed a new complete factory wire harness with upgrades, removed the AMP gauge and installed a volt meter in the dash (modified volt meter I bought on Amazon.) Bolted and tapped the AMP gause wires behind the dash. I also installed a second circuit directly from the battery to a sub panel in the glove box with six fused relays for my accessories. I installed a fused #10 wire from the alt to the battery. I have a 70 Charger R/T with a Power Master 96 AMP altenator. When you look at the dash, the new volt gauge looks almost factory. Been working on this car since 1979 when I bought it in High School. I have an electronics degree from a trade school. Electrical problems are nothing to take lightly on a classic car.

[@DeadDodgeGarage]

Yep. When I add additional circuits, like EFI controls for example, that’s exactly how I prefer to do it - with a separate panel and relays independent of the original electrical system.

[@artisan4797]

I have to say, even though you drive a brick, you are one of my favorite automotive channels. The self deprecating humor is outstanding! Keep up the good work.

[@DeadDodgeGarage]

Thank you!

[@patricklynch1962]

Back when my dad owned my '79 Dodge St. Regis, the ammeter itself got a bit melty where you could see it. I don't remember the exact circumstance but my dad immediately disconnected the battery. He disconnected the wires from the gauge, cleaned them up and joined them together. Under the dash got a three gauge set with a voltmeter. Years later, when I revived my '68 Fury VIP, I did the alternator shunt wire with a different style of fusible link because I'd had gone from a 37 to a 65 amp alternator. At some point, I might replace that with a fuse. I also disconnected the gauge wires, bolted them together and wrapped them in a lot of electrical tape. I have a triple gauge set with a voltmeter under the dash as well. Headlights got a Putco harness with relays which took a big load of my headlight switch. Much happier at stoplights at night.

[@jamesblair9614]

Good information. I hunted up. A few original date coded 37 amp alternators that had never been through a rebuilder, then found a shop who understood what I didn’t want them to do. I’m still living dangerously, but I have developed a good nose for hot wires and soft plastic. These are lessons learned the hard way.

[@DeadDodgeGarage]

They sure are!

[@bradsrestorations1085]

Excellent how and why video! Thank you

[@ricksaint2000]

Thanks Jamie , I did almost burn up my 66 Dart up several times on wiring going thru the firewall. Quite exciting at the time. Boy I sure miss that car.

[@richjordan9375]

Very nice video. I already wrote you a while ago about my planned experiment, using an under hood shunt and a later C-body ammeter designed to work that way But fitted into the gutted Challenger ammeter housing. My bulkhead connector showed signs of overheating; I had a modest stereo upgrade, but also added e-code halogen headlights which drew more power and kept tripping the breaker in the headlight switch. All of the headlight relay articles I found back then pre internet said to tap main power for the headlights off of the battery positive and I bet that’s part of why the bulkhead connector had started overheating even with the relays installed. It wasn’t until a couple of years ago that I found an explanation of why you need to hook new or increased loads like stereos and auxiliary lighting off the alternator side of the ammeter wiring. It was a big WTF until I saw the wire flow diagrams and then it made perfect sense. but I am allergic to crimp connections. I know they’re supposed to be OK if done properly, but as long as I’m pulling the plastic off the connector, and using adhesive lined shrink tubing, I am going to solder all of those connections. I may also use Deoxit-gold on all of the spade connectors in the bulkhead when I get to that point.

[@DeadDodgeGarage]

I almost said specifically in this video that I don’t believe in soldering automotive connections. I do understand why one might, but I’m a crimp guy. Get a good crimp and protect it, and you’ll be just fine. Right - even using a relay off of the battery, that power has to be replenished somehow. That’s a pretty simple way to imagine it.

[@richjordan9375]

@ thank you for replying. I’m sure you have seen far more bad crimp jobs than I have, but the ones I saw were enough for me. I have a crimper I use for solar panel connectors that might be just fine for use on the car too with the right connectors with the open U in back instead of the already closed barrel. It does the W shaped crimps instead of just squishing around around the wire.. I would be far less concerned using it on the vehicle wiring, than the crush crimper type. But I’m not gonna argue with you 😁

[@tallhair]

@@DeadDodgeGarage Why do you not believe in soldering automotive connections? More work than required or another reason?

[@MoparJimmy]

My ignition harness inside my steering column went out and it fried my fusible link and did damage to my bulk head connector. Replaced it all and disconnected my ammeter. Great video Jamie and thanks for the help with that issue.

[@PhilDodgeFury]

the amp guage terminals are definitely a better one than the firewall . I’ve got by passed wires so I’m going to add this shunt wire . Thanks Jamie happy Saturday it awesome too see the channel going so good ✨

[@DeadDodgeGarage]

Thanks!

[@jens.9155]

Ohmygoodness dude! I wish you were local. We'd hire you to re-wire our 1970 Dodge Charger. Thank you so much for sharing this information.❤

[@bartorlans5390]

I did similar to a '61Rambler Ambassador, but I used green 10-ga wire because it's my favorite color. 😅

[@allanperryman388]

My dart will be getting a shunt soon. And some relays for the headlights. Thanks

[@Hotrod_Perspective]

This is a fun lesson I had to learn recently at the Google academy on my recent BB Duster I purchased. Super fun surprise finding burnt wire sticking the under dash harness together like super glue. "mint" as the kids say

[@DeadDodgeGarage]

Oh boy! Yeah, that’s always a fun one. My brother’s duster did that ignition harness melting down thing once…

[@evanmurphy2473]

One of the 1970 Plum Crazy purple Hemi Chargers used to be around and I remember when its harness caught fire. It survived due to the quick reaction time of the owner's man serva..I mean employee.

[@antonleimbach648]

Wow, I had no idea that the Ammeter was wired this way. I thought the gauge had two wires that went to the firewall connector and that’s where the connection was made. Nothing like being showed how little I know, thanks!

[@79HurstOldsGuy]

Thank you for the how to! Just did this on my 67 Barracuda conv. wiring. 👍

[@stevenbean9706]

had two melt downs in the cummins ! i tore everything apart and put marine breakers in with one wire high output pa performance alternator . love that alternator

[@69Coronet500]

Good advice......and always carry a fire extinguisher, just in case.....I had to help put out a old Porsche 911 one afternoon

[@DeadDodgeGarage]

Yes, VERY good idea. I don’t… it’ll bite me some day

[@bookofrevelation4924]

Yep, I carry a fire extinguisher, and trusting it to work no matter how old it gets, hope it works no matter how old it gets. Big bag of baking soda might be a cheap solution to throw on a fire, my grandparents had a very old fire extinguisher in their farm house that you had to pump up with a push handle on bottom of the canister filled with baking soda with a large hose. I wouldn't have wanted to try using it.

[@Anthony-nw5zv]

Thanks for sharing 😊.I wasn't thinking about that idea back when I rewired a '70 300 and a '68 Charger. I did however bypass the original charge circuit directly through the firewall and believe me I had a positive response on starting and charging.😊

[@DeadDodgeGarage]

Yep, I’ve done that too. Common mod I… probably should have mentioned in this video

[@Anthony-nw5zv]

@@DeadDodgeGarage I wonder if over decades the factory hookup on the firewall permotes over working and failure of the charging system as a whole or in part weakening the regulator and alternator. Demanding more ampers than is possible. When both mentioned cars wiring burned they did so after I put them to bed for the night. Both cars ran like crap before hand. Honestly I enjoyed driving that 300 a lot especially straight of road 🛣️ that was dark at night with very little traffic. Smooth as glass. 😂 When I typed glass this comes up 🍷, I'm more like a 🥃 don't like wine 🍷

[@DPWheeler67]

More knowledge!!! I had never heard of this fix before today, thanks Jamie!!!!!!!!!

[@BigBoxDodge2020]

Thanks, Jamie. I was really looking forward to this video description of the shuntwire. I have to do that on my 73 W 200 truck, so I appreciate this. Let me know If you're ever coming up North- Brem. I have some things I could give you. ( car stuff) I saved this video. Yay!

[@Roosters_Restos]

I seriously should save this to my greetings list because it's spot on and informative to all. Very on point and the only thing I do different is not run a fusible link I use a 30amp breaker so if it gets to hot it kicks out and doesn't burn anything. I did once use a 50amp breaker and that was because the amps of the alternator was 75amp. Over all I love this video. With your permission I will add it to my play list.

[@sjaywjayw70]

I lost an alternater and the ignition harness connector from the bulkhead connection. I approve this message.

[@leonnekrotiuk3607]

I ❤ mopar

[@garryhatchett775]

I need to do this.

[@jhuntosgarage]

Jamie, this video is helpful and right on time. I'm off to get some 10 ga. wire to do this for my '81 Vette. Thanks for sharing!!

[@55hemidodge]

This is actually what I did on my 62 Dodge lancer GT, I upgraded it to a 120 app nipondenso alternator, i ran a 6 gauge wire directly from the alternator to the starter solenoid, the Amp gauge still works at least to show current direction. But everything isn't running through the ampgauge anymore. I think that the 120 amp nipondenso alternator would be a great upgrade for your valiant project because it provides great high amp charging even at idle for your fuel injection system.

[@DeadDodgeGarage]

Already upgraded to a one wire and added a shunt wire. Don’t know the amperage rating, but so far it seems to do alright.

[@knote4958]

1:06 Good to know because I was planning to do all of those things (I was told in forums the extra amperage would fry the bulkhead connector but wasn't told any workaround for it)

[@rogerthatgarage]

I saw you mentioned about shunt wires in a previous video, so I added one to my car While I was doing some other work to it. The Guage reads same as what you were showing. So that's good to know! I didn’t add a fuseable link though, so maybe I'll do that.

[@DeadDodgeGarage]

I’ve done a few without - but I certainly have to tell you that adding one is a very good idea!

[@brianandrews7099]

I have always “split the difference” on this mod. I really like having the Amp gauge working so I just replace the factory wires to and from the meter with much larger gauge wiring. The relay kits for the headlights is pretty much a mandatory mod for me as well. If you want to switch from incandescent to halogen headlight bulbs, it is the only way I have found to avoid constantly replacing headlight switches and the easiest way to say goodbye to headlight that dim when the rpms drop to idle. I have more fear of the firewall plug melting down or shorting out than the amp gauge. I need to rewire at least the dashboard forward on my ‘64 Barracuda and I was seriously considering just making my own wiring loom and leaving the big plug out altogether. In addition to a fire due to high resistance, a short that causes complete loss of headlights at 55-70 ain’t much fun either! Been there; done that … don’t care to rinse and repeat! Good content, as always!

[@DeadDodgeGarage]

That’s how I like to do it! And yes, headlight relays are the way. Did a video on that subject way back. Also, it’s not a short that causes the loss of headlights at speed - it’s the tripping of the headlight switch’s internal breaker. It only ever seems to happen to me on high beam… and it’s quite terrifying on a back road in particular.

[@timcoffman8010]

Thank you

[@brokentoolgarage]

Nice job. It is good too see how others tackle problems. I found the charge wire from a Taurus (2000ish) has a ring terminal and boot that fits nicely on our alternators - and it is like 4ga. Always a pick at the junkyard 😀

[@Alecs_automotive_adventures]

This is just what I was looking for, need to do this on my W100

[@louislepage5111]

Love the Care Bear reference 😊

[@ohar7237]

If you left your heat gun at your shop, and you're doing electrical work at home, it turns out that a standard output hair dryer, on high, will suffice to shrink heat shrink tubing. It turns out that they're actually just generally useful for working on old wiring as well, because if you gently heat up the insulation on the entire length of the wire (or at least the section you need to reshape) it'll make it a lot less likely to crack and need to be completely replaced. So I actually bought a regular hair dryer for the shop as well.

[@ohar7237]

I wonder if it's possible to alter the factory ammeter to be more sensitive to loads, and thus read correctly after the shunt wire is in place. I may need to try and take one apart to figure that out. That would be a neat trick.

[@dantupper1784]

Great Vid!- right on point.Thanks.

[@gregpanek523]

I have a '77 Dodge Van, it had a meltdown at the Ampmeter connection behind the gage from before I bought the van. It's how I got it for cheap He didn't know what was causing the problem and was tired of it, I knew exactly what was wrong. So I got it home, tore out the dash, and went to work. I unhooked the wires and stuff and removed the dash I slipped two oversize sections of shrink tubing over one of the wires got a bolt and self locking nut (not a nylock) and bolted the two wires together in a straight line with a star washer between them. then slid one shrink tubing over the connection, shrunk it then did the same with the second one, having a solid and protected connection then I did the "shunt" wire like you did. Then I went online looking at voltmeters My van has the 4 gages in a circle with the ampmeter hangs upside down, making it a little difficult to find a replacement. I found one for a Mini Cooper that looked about right and it was upside down. so I bought it and waited a few days It had a white needle. I took the gage out of it's housing, put paper between the needle and gage and sprayed it with floresent orange spray paint. that worked so excellently that I touched up all the gages needles with it. I did a little material removing from the back of the gage then using black RTV as glue, I cut a plastic container to get apiece of thin flat plastic to make some extra background for the gage, cut it to shape painted it satin black, syliconed it to the back of the gage. drilled some new holes in the housing and installed and wired it. once together, it looked factory original, needle went the right direction The font was slightly different (the only giveaway) but if you didn't know, you wouldn't notice, the various volts were in place. Had full monitoring of the charging system and the Mopar fire hazard was eliminated. I also used a high amp circuit breaker from behind a dash of an old Peterbilt truck instead of a fusable link. I hate fusible links. I prefer replaceable fuses and circuit breakers.

[@Ulford]

Love how you explain how things work. Learning a lot. Thanks.

[@beljames1563]

Great information.

[@VintageLifeCars]

Great video. Whilst watching I definitely came up with a question for you about this. When I remember what it was I'll ask...

[@DeadDodgeGarage]

Sounds good 😅

[@danpickar5442]

Thanks I learned something yet again!!

[@blahblah4125]

You are a compendium of useful auto lore, thanks for what you share. Looking forward to more Turbo EFI V6 wins and more on your Dodge trucks. I really don't prefer to see your videos on the complete and awesome muscle cars like your own Demon, Chargers, and Challengers. But that's only because I am super jealous LOL.

[@DeadDodgeGarage]

Understood 😅 lots more to come! Thanks!

[@TAVOAu]

Nice video Jamie. Did Chrysler Australia know something, when they switched the steering to the correct side? Our earlier cars just had the engine harness fed through a grommet in the firewall, no junction box. I have another suggestion for the name of that instrument, what we commonly call it down here "Amp gauge". There, another lesson in speaking Australian 🤣 Oh, we do have a fear of that gauge burning the car down here too. I am glad they included that gauge though, one night driving, the lights seemed to be just a bit (lot) brighter than normal. First thing to look at, the ammeter, amp meter, amp gauge, which was pinned hard against the C. That told me to instantly shut that motor off, and whack the old style flip flop regulator to free it off.

[@bookofrevelation4924]

Decades ago I drove a Plymouth Horizon Hatch Back thousands of miles through states along Eastern, Southern, Western and Northern Coasts and Borders of USA, the voltage regulator quit regulating, fully charging battery until headlight low beams burned out and battery boiled acid out while pushing the sides of the battery out, then the regulator stopped charging at all before I could get to auto parts store to replace Voltage Regulator, headlights and battery.

[@bookofrevelation4924]

Likely was the high powered stereo amplifier I installed that caused the Amp meter in my 1969 Charger to burn out causing me charging problems for a long time before installing a heavy duty underdash Ampmeter that got very hot.

[@andynelson8725]

Your Vids are amazing, I owned 2 69RT's Chargers. Hind site etc.... You have amazing info. Your presentation is great. I do enjoy your satire. You have an amazing ability present great info and aply humor. THANKS Andy

[@dwaynepadgett9322]

Nicely done!

[@minnesotatomcat]

I had a 79 powerwagon and the ammeter smoked my whole cab up one day, melted the housing. Found a nos ammeter and it worked fine for awhile, I would reach up and feel it regularly cause I was terribly gunshy of burning it down after the first time, then damn it if it didn’t do it again while driving down the road one day. This explanation makes great sense, I always thought that was a stupid way to route the wiring, I wish I’d have known about this shunt wire hack back when I had the truck, wondering now If that would have saved a pair of expensive nos gauges.

[@LongIslandMopars]

I'm late to watching this video. My dad's 66 Coronet has its original bulkhead connection for the 59 years and 207k miles that its been on the road. Always had a stock alternator and never any extra accessories. Its survived but in the Spring i may be doing this. You're the best Jamie. Happy New Year.

[@DeadDodgeGarage]

Our wagon is still stock too. Demon is stock. Etc. But it’s a good idea.

[@LongIslandMopars]

@DeadDodgeGarage I hear ya. It's on that list if you know what I mean ....😎

[@NuxDriver]

Good idea to disconnect the battery when stored, even overnight. I had a cheap Chinese starter relay go bad on my 67 NYer. It started cranking continuously. The starter cable caught fire.

[@ericwilson2585]

I've always liked a voltage gauge after putting in the bypass wire. But the only vehicle I've ever put one on was my old 78 W150, and it had both a volt meter and a ammeter from the factory.

[@chuckcafiero4546]

thank gawd you got away from that millenial banger. you are a great auto electrical tutor

[@DeadDodgeGarage]

Thank you!

[@r.davecarr6010]

If you add a fuse and not a fusible link, be sure it's a type of fuse and fuse holder capable of the current it's expected to see. I tried using a 50 amp blade fuse and fuse holder in my Newport to power my Mercedes cooling fan, and the fuse holders would melt down after only a few hours of use. I had to switch over to a fuse holder that bolted in the replacement fuse. Ever since then I've had no problem, and I'm running a 150 amp alternator to power my car. I'd be happy to provide pics of what I speak of.

[@DeadDodgeGarage]

Oh wow. Yes, when I do this, I always use a screw type fuse and holder. I thought I explained that this needed to be a heavy duty solution in the video.

[@r.davecarr6010]

@@DeadDodgeGarage I'm sorry if I missed that. I had mistakenly assumed a 50 amp fuse was a 50 amp fuse was a 50 amp fuse. Silly me. Several missed shows and cruises later, I learned my lesson.

[@brkooduh66]

good video. thanks. the element on one of my ammeters burned up, left me stranded. that's when i learned about this problem the hard way. it burnt up because of the bulkhead connector was bad, that is were the problem starts. i did my "shunt" differently but essentially the same. also i no longer use an ammeter, i like to convert to a voltmeter gauge when i can, which wires in differently

[@jfv65]

I had this exact issue on my 61 Peugeot 404. I converted it from generator to alternator and guess what, it started stinking from the dash... i caught it just in time so i bypassed the guage in the dash. That got me home. I could have used this video to improve my charging conversion.

[@ntahater]

As shown by your vom, voltage is a good reference

[@DeadDodgeGarage]

Well… yeah. But we already *have* an ammeter.

[@jimbo5728]

If you want the ammeter to deflect more, I believe you could put your shunt on the firewall side (near where it normally passes through twice, so theres less wire, albeit less convenient place to work). Then remove the shunt that's mounted on/in the back of the ammeter. This increases the sensitivity of the ammeter, without sending all that current through the firewall twice. Right now the ammeter is seeing a lot less "signal" to react to. You'd allow it to see more by getting rid of its old shunt on the gauge. This would just be to satisfy some OCD, or possibly a customer who wants the gauge to "work better", not really necessary.

[@jimbo5728]

Glad I'm not the only one who thinks a split ring connector is superior to the fully open slip on ones. I never use the latter.

[@scottday8]

Dude! Your the best thank you for the info and showing the gauge in action and I love your “ warning “ don’t blame me for your mistakes lol

[@Paul1958R]

The ammeters used on 1G Ford charging systems (c 65-73) were all shunt type. But they were actually 'over shunted' to be safe and the ammeters hardly moved.

[@zerogmopars746]

I have done this also, but it has a downside. You now have two fusible links in parallel feeding the dash wiring, so a dash/ignition short really won't burn the fusible link before damage to the dash/ignition wiring. You want to disconnect the original alternator output that goes to the bulkhead, and connect that wire/bulkhead connector to the same side of the fusible link as the bulkhead battery connection. This splits the load on the connectors going to each side of the ammeter, but the total load is protected by the single fusible link that is sized for the main dash/ignition wire sizes. If using a fuse in place of a fusible link, it should be a "slow blow" fuse like a Mega fuse or ANL type fuse. They are rated different also. Regular fuse will blow/open at the rated current, where the slow blow fuses are rated to only blow/open if the current exceeds the rating for many seconds. This prevents temporary current surges from blowing the fuses.

[@DeadDodgeGarage]

A good point. And agreed - when we have used a fuse for this, it has been a Mega Fuse or similar.

[@timrayburn2461]

Great video...thank you

[@craighansen7594]

I considered doing this to my 70 Dart. I repaired the overheated bulkhead connector. When I studied the wire schematic and realized the charge path that you thoroughly explained, I didn't like it. I would really like to replace the ammeter with a voltmeter but I want a gauge face that mimics the factory ammeter. Does anyone make such a voltmeter? I could take a generic or salvage voltmeter and repaint the face but prefer the bolt on part if it exists.

[@DeadDodgeGarage]

Red Line Gauge Works can build you one, I’m sure. I installed one from them in a ‘71 Challenger. It was very nice.

[@LSSindustries]

Great video as always

[@scottk6958]

Another great video as usual! Perhaps you need to do a video on a voltmeter swap. At least you won't have to say "ammeter" any more.

[@DeadDodgeGarage]

I don’t really believe in volt meter swaps. I’ve done one, I guess.

[@GeekGinger]

After dealing with the wiring in my 71 Camaro, which was hacked together and very crispy, I bit the bullet and got a complete upgrade wiring harness from American. It was NOT cheap and it WAS a pain in the ass, but I've thanked myself many times for doing it. It did, however, not come with any provision for the ammeter. In fact the instructions said that it was on purpose and to switch to a voltmeter from a later second gen. I don't love that as I'd like to keep things at least looking original at first glance, even if it does have an HEI and a 120A single wire alternator but it's a small thing. A small thing that bugs me every time I look at it. 😁

[@DeadDodgeGarage]

Don’t know about your application specifically, but for the ‘71 Challenger (also an American kit,) the owner was able to have an amp gauge converted to a volt gauge by Redline Gauge Works. It matched the dash perfectly.

[@geoffreysmith3196]

I understand the issue with traditional analog ammeters is that they need to be wired in series between the alternator/generator, and the load (the car's battery and accessories). And having that go through a gauge on the IP this is a real problem when your alternator is able to put out 50-80amps at 122VDC. That IS a Fat Wallop of current that you really don't want to go through to the dashboard and back on its way to the battery. (If you do the P = IE math, 50amps @ 12VDC is 600 watts.) But on those 60s-70s era Mopars I used to have, I found that ammeter to be a handy item for keeping tabs on battery and voltage regulator condition. If the ammeter didn't return to light charge within 10 minutes after a cold start, that was a sign the battery may be weak and might fail to start the engine once the sub-freezing weather set in. If the ammeter registered what appeared to be constant substantial (say, 5amp) charge, and never returned to center, then that was a flag of either a weak battery or of overcharging, and that needed further checking at the battery with a volt meter. I've always found ammeters far more useful on the dash than simple volt meters for heading off future problems. Does anyone make an aftermarket ammeter that uses an inductive pickup that can be placed around the battery cable (that sends a low voltage & current signal to the "ammeter" at the panel - said "ammeter actually being a simple analog voltmeter that can read both positive and negative polarity signals form the inductive pickup)? Thanks for another educational video. I do learn stuff from your videos, even though it doesn't seem that way.

[@DeadDodgeGarage]

I don’t know the answer to that, but it’s an interesting thought. Thanks!

[@72roadrunnergtx]

Well I’ll be, someone who recognized just what the original purpose of the ammeter is/was. To monitor battery charging/discharging. To be clear, there should be no vehicle loads registered on the ammeter while the engine is running, only battery charge/discharge, fully charged healthy battery will have the needle centered, little to no current flowing through the ammeter. All factory loads should be covered by the alternator on the alternator side of the ammeter.

[@guvsgarage]

Awesome. Next job on the list, then the diff.

[@olmo-c9e]

wondering if there is a voltmeter to drop into place of the amp gauge. So that with minimal rewiring one could have better charging feedback.. Also LOVED your intro, wondering if you were referencing any previous comments.on other video..... hum. Anyway , as a retired EE , I'm comfortable with you using different terms to refer to the same item, instead of the book term. It introduces people what other people may call it when they research their repairs further. Also, I assume most of your viewers know this channel is mostly for entertainment and not college class in DC Circuitry, nor a Trade school class in car restoration. That being said your helpful hints are pretty dang good. And I'll keep watching for all the above. By the way ,Tomato or is it Tomato?

[@DeadDodgeGarage]

I sure hope they know. This is just KZbin after all. Haha. Various companies out there make a nifty conversion volt gauge that looks the part and drops right in place. Redline Gauge Works is the one I’ve dealt with, and their part was very nice. You’d better believe I’ve had some creatively obnoxious comments over the years… and it is *definitely* TOMATO. Thank you!

[@YODAMAN5]

AWESOME info Mr J. I have a 73 Challenger I had a problem with that wire from the alternator getting HOT all the way to the harness connector under the sterring colum. Your way sims to be a better idea as to my colum get HOT above the key ingition. Im going to try this sett up. Dont worry I wont have my lawyer contact you if my ride burns up...lol MOPAR 4 EVER.

[@DeadDodgeGarage]

Good 😅 for the ignition switch wiring, you’ll want to cut and run the unhappy wires around that plastic connector. Very common problem on E body more than the others for some reason, but I’ve seen it in As and plenty of trucks too.

[@bookofrevelation4924]

Any thoughts why the movie Vanishing Point used a 1968 Charger named Beast to chase the Hemi Challenger? I'd rather had seen the 1968 Charger with a Hemi being chased through several states. That is what I did in 1981 at age 18, only a Porsche passed me.

[@DeadDodgeGarage]

You mean the 90s remake. I don’t believe in that one…

[@4339jk]

This is a good idea even w ZERO add ons....!!!

[@DeadDodgeGarage]

That’s what I’m saying! This car has no upgrades at all.

[@4339jk]

@@DeadDodgeGarage Don't forget the headlight bypass if you didn't do that already. I bought a kit but you can explain it...

[@alcyr5655]

Lesson I learned back in the 80's. Properly torque down the nuts when reinstalling wiring to the gauge. Finger tight is not adequate. Lucky no fire, but several frustrating moments of complete power loss.

[@DeadDodgeGarage]

Yes! Agreed. And was wishing I had thought to mention that during editing, but let it go.

[@alcyr5655]

@@DeadDodgeGarage PS I often heard about the shunt wire. Over all these years it was never explained like this. Thankyou

[@cbobmonster]

Hey smashed camera just means you’re working. That’s mechanic stuff. Great video.

[@lanceneuman9528]

Thanks

[@michaelasher8084]

Jamie l will be doing this to my charger but one other thing to help out the headlight switch is putting relays in the headlight wires after the switch and highbeam switch. Only thing is for me its a little confusing for me wiring them up. l know l need to do this to reduce the heat in the headlight switch which will make it last longer and less stress on the wiring. AKA heat melt down lol

[@DeadDodgeGarage]

Absolutely - and I did a video about that upgrade *years ago* now, which can be found in my Electrical Guides playlist.

[@TheMOPARISBEST]

How about a video on the blue charger. Got me excited seeing that

[@DeadDodgeGarage]

It’s waiting its turn! We’ve got a lot to do to that thing…

[@Spawndukes]

The last car i burned to the ground was, in fact, a Mopar. But instead of crap wiring it was caused by gasoline soaked seats and a match. The talking dash was the last thing to stop working.

[@DeadDodgeGarage]

Impressive 😅

[@PeterStuartJr]

Thanks for this! I'm restoring a '65 Barracuda and this along with many of your other videos have been a great help and reference. Any reason not to run the shunt wire across the front of the engine, since alternator and battery/starter relay are both towards the front? I've got a one-wire alternator with a shunt wire running across the front (tucked in near the radiator) and to the positive battery terminal. Great info on the fusible link, I hadn't heard about sizing 2 gauges smaller than the wire its protecting. I'm filing that in my long-term memory, so I'll likely forget it tomorrow and have to come back and watch again :)

[@DeadDodgeGarage]

No reason at all - I just prefer to hide my work as well as I can. Haha. You bet! Thanks!

[@mikeleuk]

My 68 GTX had the battery relocated to the trunk. Headed out to work one morning and saw smoke coming from the trunk. The aftermarket amp meter almost burned that car to the ground! So lucky I saw the smoke before that happened.

[@DeadDodgeGarage]

Oh wow. Gary’s 300G tried to do the same thing in his garage one evening. Thankfully he hadn’t gone to bed yet and smelled it.

[@PeckerwoodKustoms]

Scorpion!!! Want another one but cant afford one now...the 2.6 and turbo was fun...not blinding fast but quick enough to beat WRXs when they first came to Australia....LOL

[@DeadDodgeGarage]

Even NA this thing really doesn’t feel like a slouch to me. It’s pretty good fun.

[@rosscurtis896]

not many can tell it like you can sir... this one is a great one... wait, maybe we can call you the great one... naaaah.... Gretzky has that covered. But wow, great video on this , made me smarter

[@noberet]

Finally! Thank you!

[@DeadDodgeGarage]

Right on time as usual…

[@MetallicAH2O]

I don't remember what gauge they came in but Navistar (international) trucks use/used fuseable links and we used to replace them all the time. It could be a good source for new wire that isn't the parts store.

[@StraightLineCycles]

Bulk head connector for the alternator is almost the same on my 97 f150, but it had a resistor.

[@DeadDodgeGarage]

A resistor? That’s interesting.