YOU'RE LOSING PERFORMANCE! How to Measure Voltage Drop and Test Ground

MORE Voltage means MORE Power! How can we determine where we are losing voltage in our custom car audio system? Where is the best spot to mount a ground wire for an amplifier? Let's test our ground wire to find out and measure voltage drop!
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Car Audio Fabrication - Master Car Audio - Design, Build, Install

[@CarAudioFabrication]

Hey dudes! Who already knew about this test? Who didn't? There's no shame in learning something new! What else would you like to learn?

[@samuelpurvis8786]

CarAudioFabrication so when I’m playing my music with my car on and running when I hold the rpms over 2000 it keeps the amps on when it drops below it cuts them off two 300 watt amps running of off 4gauge wire each amp powers a q power 15 please help

[@danyo5509]

How do you know how much your stock vehicle alternator amperage could handle including accessories + amplifier?

[@timhenry8475]

samuel purvis Is your wire OFC?? Using ofc vs CCA can definitely cure this issue. Check for corrosion at the terminal connections. At the battery, and at ground. Could be an issue. Not having a rock solid connection can be it.

[@agent1543]

I didn't know you could read voltage on the same polarity. Learn something new everyday.

[@georgebrown3007]

Is it best to run ground to a 2nd battery or on the frame

[@TBO207]

If u don't want to buy extension leads use speaker wire and do the same thing to measure resistance it works well

[@jordanlara751]

How would you use speaker wire?

[@tymorrow4349]

@@jordanlara751 wrap one end around the positive test lead of your multimeter. (Be sure to check the resistance between the speaker wire) Then stick the other end of the wire on the positive terminal of your battery. Now use the negative lead to test your ground.

[@pranays]

Any wire you just need to minus the resistance of the wire and leads.

[@GreekPower]

Thanks for this! I bought extensions and they won’t work! I was racking my brain on how to fix this issue. This helped me a lot! Now I can test

[@bablobhai]

oh man how many times am i gonna say this.. you are just a HUUUUUGE source of good information and a very good teacher.. i didn't even know small things like these matter so much.. i have so much respect for you buddy.. literally the best audio system channel out here..

[@CarAudioFabrication]

Really appreciate that! It's not always easy, I was up til 2 am last night editing this, but comments like these make it worth it.

[@BurningDownUrHouse]

This is by far the best car audio channel on KZbin. Thanks again Mark!

[@CarAudioFabrication]

Doing my best! Thanks!

[@heyimclancy]

Agreed

[@T-HobbiesG45]

Has to be Doug in disguise

[@pipelinecowboy]

I concur with thT statement song ! 💪🏾

[@reekinhavok420]

I dont know about the best maybe the most professional.

[@stevenknutson1521]

Video idea; $3 rca vs $30 rca signal cable differences . Love the videos! Always well demonstrated!!!!!

[@ericMT]

@Mark Seven quick maths

[@abdulsajid1518]

I have a problem in my sony amplifier it is giving red 🔴light and it is not onning please 🙏 put the vedeo open this

[@carlosesparzavazquez4753]

@@abdulsajid1518 you mean you have a red light on , on your amp and your car isn’t on ? Sounds like you wired the remote to a constant current fuse

[@minhajuddin6607]

@@abdulsajid1518 amp is in protection

[@superchile9640]

Great video Mark. Thank you for always improving the craft and helping others (all of us) along the way!

[@chadlavender5267]

Man I Appreciate your Clear speaking of words & Exact process of the issue at hand. Your videos are Top-Notch and have Evolved my car audio knowledge. Thanks

[@jeremyjoseph2317]

I learn a lot from you, simple things that i thought was not a problem, thanks bro am all the way from the caribbean (GRENADA)

[@melvin_0bviously]

This video should be required viewing for every tech touching automotive electrical components, whether handling installs, retrofits or forensics. Serious value here. Thank you!

[@usagimoto1423]

Love this. Thank you. Thank You. You speak so clearly, Not too fast, Not too slow; just perfect. Don’t add any life stories or personal things, Straight to the point. God Bless. Definitely learning car audio here. I’m not big on car audio. Ratio(Handling/Engine/Audio) Car wise is (50/40/10)..... so less is more for me. What’s a good small amp to control 2-4 speakers and maybe a small sub. Toyota MR2 (SW20) 1991 version.

[@alexvidal6972]

Great video Mark, I'm grateful that you do what you do, u take the time to explain it step by step

[@OfficialHelixx]

FLIPPING OUT!!! THIS IS WHAT IVE BEEN LOOKING FOR! THANKS! Subbed!

[@d.crosby3799]

Great video. We need this level of accurate sharing in everything! Save that money.

[@cartruck1070]

I've done a couple basic installs over the yrs and never thought about this. Great info.

[@ryanfahey640]

Awesome vid Mark! I recently needed to test for voltage drop, the ultimate problem being with my fuse block. Accidentally installed a washer between the fuse and block, which caused a high resistance failure point. The fuse for the subwoofer amp began to melt during some serious hip-hop bass segment, but never went full-blown. Won't be making that mistake ever again. I get less than .1 volt drop after getting a new fuse block. The factory amplifier ground points under the seats were never used, and gave me a great grounding spot! I was aware of the resistance test but never load tested a ground point before, that's a great test!

[@ISIDROYIII]

Well you gave me somthing todo when I get home, definitely interested on the outcome of the tests

[@Japone81]

Man this video is so simple and informative thanks mark

[@okroman6953]

You The Man. Always GREAT Knowledge. THANK YOU!!!!!!

[@hermankangoo4744]

Bro you are really good at what you do I learn something new every time I watch your channel thanks so much. 👍👍👍👍👍👍

[@zumik83]

Haha, I performed my car audio instalation in my backyard, so I'm not a proffessional audio installer, but I do have 14,20 V at the battery and 14.15 at the amplifier... so thanks Matt for clearing things up !

[@gieauto7175]

Used voltage drops for years and would make one small comment on checking your grounds. The body grounds are usually much small than the power side. This one area is easily overlooked when you see a large power cable going to the engine block followed by a tiny wire going to the body. And you have a excellent series of videos didn't start using plastic until I viewed your site.

[@MarioRicci3645]

Your video's are so insiteful and so easy to comprehend.

[@josephgalangjr.2984]

such a big help, keep on feeding our minds. again, thank you....

[@thomasmccaslin4411]

Awesome simple content bro. Appreciate it

[@pix_by_joshua]

Excellent info! Thanks for sharing.

[@ionetuning6231]

hello Mark,a huge thanks for being my mentor,i m geting toghether all the parts and tools i need to instal my sound system.i have a huge space where the spare wheel goes 60 cm x90 cm

[@alexerstube]

Thanks for this video man I always wondered how to test good grounds.

[@svitroful]

Excellent with example - Great usable information - thanks Mark.

[@sivonparansun]

Great video! This may be the answer to the hiss i am hearing with my new amp

[@DJ_Blaker]

Great video! Learned something new again!

[@SparkedEd]

Another great video Mark

[@adamfunk9605]

There's one thing you failed to mention in the video that I noticed Oh by the way excellent informational video, when you're describing testing the resistance the positive lead goes to check your possible ground locations the negative leave goes where to the battery or to the battery cable it's never specified where it goes. Lot of folks wouldn't know, either way excellent work thanks for the information got a good thing going keep it up

[@PoppaTInstall]

Good info Mark. I like how you explained voltage drop.

[@CarAudioFabrication]

Thanks for watching

[@matthewtalley3024]

That explains alot of my voltage drop, I have 4v of drop under heavy load at specific frequencys and this helped me realize I had to small of a ground wire or cca and not ofc got it fixed now thank you so much

[@gideonx5]

Love your content, thank you for the informative videos. Would you be able to do a video on how to work around the smart alternators in the newer cars these days? Thank you.

[@dairyjerry2455]

What a great video, spot on! My builds almost done this video will allow me to sleep at night now lol

[@HifiVega]

Great pro tips! I never check my grounds for resistance, but I will now... You’ve shamed me into it 😂

[@smokingzombie4880]

thanx man i have a jeep wrangler and my ground is on the cargo bolt and ive been feeling as though i have not been getting the best performance out my system glad i stumbled across this video thanx man

[@stephendverner]

Wow testing resistance on my ground location…I should know better. Gonna do it now. Also measuring voltage drop, too. Great information well explained.

[@uptobatentertainment]

Fire explanation & video thx!!!

[@kyle3420]

Very well done. I like that you took the time to explain that voltage drop measurements are to be taken while the system is UNDER LOAD. I will say that the voltage drop measurement you are taking is proportional to the current of the load. Therefore the voltage drop will be higher when you turn up the volume (Vdrop = I_load x R_wire/connections). To add further information, you are testing the voltage drop due to the electrical connections and NOT the system drawing more current than the alternator is capable of providing (therefore resulting in the voltage dropping to battery voltage). You should do a separate video explaining that the alternator can only provide the current it is designed to and that adding extra batteries is not going to solve voltage drop issues. In order to maintain 14.4V+ you need to have an alternator capable of the system demands (or multiple alternators).

[@uptobatentertainment]

kyle3420 thanks for explaining in full what should have been included in this video ... Lots of ppl including myself were confused like how are u dropping .05 volts full tilt .. now I understand better thanks

[@JeepVsix]

i got all my installation equipment ready to get intalled, glad i saw this beforehand. thnx for the vid. would like to know more about installing multiple amps

[@chrisoconnor3119]

Running multiple amps, i run seperate grounds and positives or a large enough one into a distribution block(1 positive and 1 negative) Make sure your sub amps grounds are as short as possible. No longer than 18 inches..shorter is better on the negative side

[@Skip01]

Have you ever done parasitic loss? If not, id love to see you cover that as well.

[@VanLifeKen]

hell yes alot of people need this!

[@voltan91]

Thank you very much! I was waiting for video like this :)

[@CarAudioFabrication]

glad you found it helpful!

[@khunigan]

Great video. I was always told its better to make yr own ground instead of using existing ground screws or bolts. I've had success with both. Depending on location & voltage. What do you think? Thanks

[@thedave1602]

Good info dude. Thanks!

[@kennethconklin7786]

Thank you. Great help man. 🖒

[@brandonmiddleton9605]

Very true video if you do it exactly how you did it I found a tone of resistance for my amp ground the amp was getting hot and clipped now I found a better ground it definitely improved the performance and power of the amp 👍

[@ojsimpson7129]

i am putting a 600 rms system i was goin to go with a orion 4 gauge amp kit but after watching your vid i aid the extra $4 and got the knukoncepts ampkit and am so glad i did thanks CAF!!

[@honewaatamokepumipi8135]

This is the only real audio channel on here. Period.

[@ogairbender3175]

Keep up the grind my man,just dropped by to say hi buddy 😎

[@heyimclancy]

Subbed man, your a great teacher cheers

[@josephhenson828]

I didn't have any voltage drop when I checked the other day but I rewired some speakers and now I have a ton of noise weird things going on I'm going to redo them and check my grounds. Thanks for the video

[@rohanmudhale]

Very informative video.... Thanks... 👍🏻🤟🏻

[@seansean9107]

Great content ❤

[@divinesiliva7964]

I just noticed that bro thanks keep up the good work

[@getstuk87]

I don't usually thank ppl on here, but thanks. Learned a ton in a short span of time. Hoping I don't forget it all.

[@jayhardy4062]

Awesome video would you use the same principles for testing the voltage drop for the speaker and sub woofers wiring to test speaker wiring is Adequate?

[@2Fast4YouCL]

Very good video

[@dave7421]

Your explanations are great and easy to follow.. Thanks mate !

[@Class00499]

Great Info!!

[@CarAudioFabrication]

Thanks Douglas!

[@eycm.8195]

Nice video i dint know that mode of the tester 👍🏻

[@tommygreist9560]

Well taught.

[@sms9106]

Excellent info.

[@CarAudioFabrication]

Thank you!

[@promo130]

Great video

[@trealwilliams1563]

Man... Great Content! I subscribe👍🏿👍🏿

[@hooptastic_hippie8522]

i have that exact amp kit in my car and it is a damn good kit

[@jonathantenorio8829]

Great video. You can also test out what spot of your alternator casing is the best ground when your doing the big 3. I ran a 2/0 gauge wire from the front battery to the rear frame under the car to get better ground in my trunk space but this is great info I will check my resistance soon and go from there

[@shubhamparashar1852]

What RMS system are you running bro?

[@jonathantenorio8829]

@@shubhamparashar1852 only 900rms at the moment (not clamped) I haven't tested my system I've been just doing my own thing. Currently this is my smallest setup. Taking it easy

[@randabuffer6562]

Great vid!!!!

[@mfdmakvutsriea]

Hey mark. Thanks for all your videos. I realize this one is a bit old. I I'm looking for a good ground on the same vehicle. I assume you drilled into the body for that location? I also used that cargo hold down is a ground on my previous amp which died after a year in this vehicle. I don't know if it was because of a bad ground or because it was 20 plus years old 😢. Thanks again!

[@Circassian55]

Thank you sir

[@foodhatesme]

I used jumper cable wire to power my amp, and run both power and ground from my battery.

[@luie771]

Awesome video!

[@CarAudioFabrication]

Dang that sub in your picture looks beastly! Thanks for watching!

[@luie771]

@@CarAudioFabrication no problem. Always like to learn new things to add to my installs. You should take a look at them subs made by Hutchinson car audio. I run eight of their 12's and couldn't be happier.

[@uptobatentertainment]

luie771 any videos?

[@superchile9640]

Great amplifier wiring kit. I have the 4 gauge kit in one of my vehicles.

[@CarAudioFabrication]

Very nice 👍

[@rx720bfc]

this was interesting, i just tried all these. My audio battery and car battery are in the trunk. rest voltage was 12.7 volt across anywhere i tried .. resistance from all my wiring was 0.00 including my earth points (rear folding centre seat mounts) i'm using 2/0 ofc for everything.. The engine bay fuse/relay box has 2 positives one from the alternator both show 12.67volts (i realized after my interior lights were on if that makes much difference) the only thing i couldn't test was the resistance from fuse/relay box positive to my trunk glad i found this it helped alot since i am adding a 8k rms amp soon and i am pretty positive now my electrical is looking healthy... only thing i have to do is beef up my 140amp alternator

[@autasticreefing211]

Hi great video but a 2.46 what are you connecting the black cable too? Is that the negative from the battery.

[@brian85578]

Good stuff

[@DX-jn6mr]

i used my seatbelt bolt in the back, sanded the heck out of it and put washers on both sides with a locking screw and it’s worked better than grounding to my battery

[@Nate75757575]

Do you have a video on how to set up a power switch for an amp if we aren't using the remote turn on line. Like a stereo rocker switch style turn on.

[@tonyreaudio6579]

Is a highlighted pinned comment a good thing I just know you make great videos Mark keep up the great work man Thumbs Up

[@russellburgan9023]

Great video. Thanks Mark. I knew there should be a way to test for ground connection

[@moejr14]

Your the best dude

[@saint6563]

"Next Level"

[@Kid617]

all videos are so helpful where can i download the 40 hz test tone

[@Bertman_5429]

I saw when finding the grounding points one side of the lead coming from the multimeter was used to find the ground points but the other was connected to the battery negative ground. Is there another way to test, like connecting the negative to a seperate ground block then testing. The issue I have I am trying to find a long cable that twill go from the front to trunk for ground points. By the way, excellent video!!!

[@ColeAviation]

@CAF - I just installed a coustom box in my sons 2008 Infinity G-37S and the only way I could built it to get his 2 Duel 2 ohm Skar Audio DDX12’s and Skar 2,000 watt amp in the SMALL trunk was to put the subs facing up with them mounted on top of the box. My question is.., why does it hit harder when the trunk is open? 🤔 I always had my subs facing to the front or back in my younger days of systems. Lol. I feel like I’m not getting the full effect out of the subs. 🤔🤷🏼‍♂️ Thanks!

[@DameJM3]

Do you have any experience with Infinite Baffle installs? If so do you think you can make a video about one. I recently done my first one in hopes to save space and want to hear your thoughts on them.

[@JuanRodriguez-ev6nw]

This right here!!!!!

[@djsunthe1]

I like the video and appreciate you sharing you knowledge. It would be cool in a future video if you woudl run a purposely smaller gauge power wire and see what the differences are? Not everyone needs 0 gauge ya know?

[@metaldreams3595]

They recommend different gauge wires for different voltages.

[@manitobamanitoba1796]

Ty for the video.....how much performance loss cam someone expect from a weak ground? Ie 10%...20%??

[@Gus247365]

great video - very helpful.... I didn't know about measuring the voltage drop in that way with the DMM! :) Thank you

[@ScottyPerkins]

How did you go about extending the test leads from the battery terminal to the back of the vehicle?

[@talrahav641]

Hi, so to check the OM I need to put the black wire of the avometer to the disconnected minus cable from the battery and the red wire on the chassis? Thanks

[@matthewderry1728]

Love your videos they actually do help determine alot of people's, I'm having an issue myself, I purchased a pair of 10 inch DB Drive G2s 4 ohm and I'm wired at 1 ohm but when I turn my gain up to halfway I get popping noise, not really clipping but I know there's not to much power I'm literally right at RMS power rating on amp to subs, I've checked all grounds and power and even speaker wire it's 12 gauge, using 1/0 gauge for amp and subs it's just at high volumes I get 1 or 2 popping sounds but I'm at only 80% power as far as reaching RMS power. Any ideas?

[@tylivinlife2238]

Figure it out? Sounds like my issue

[@gabrielr6679]

So how do you test for ground when you connected a secondary battery positive to positive and negative to negative from the primary battery which is in the front stock location?

[@wassupBGHS]

For car testing, is the fluke 107 multimeter all I need, or do I need like the more advanced models like fluke 117 in your video?

[@etmesi]

I learned back in the 80s using an opened box for subs allows woofers to travel as though they are in a lot huger box. Then on one woofer reversing polarity each woofer no longer cancels each other out. Using seas foreign 13 inch woofers sounds great. Music used to test Patrick O’hear David Helping examples shows the highs and lows better than like rap 60 db bass. Give me comments what you think. I love learning.

[@ae86fanftw42]

Hi I was curious on how I could run a 5 channel with all my speakers being component speakers on my 2010 Volkswagen Tiguan( LOL I have more of a mechanic background than an electrical background) but I’m getting infinity kappa 60.11 cs for all four doors and they come with passive crossovers for each woofer and tweeter so how would I go about parallel wiring each front and back speakers to get 1 ohm each because my Kenwood amp is rated for 2 ohm speaker.( I’m sorry for wording this probably wrong but I have no ideal what I’m doing)

[@donyates749]

Stock alternator 2015 corolla and have a -1/0 ofc power ground and big three plus couple extra block to body grounds because unibody crap, 400$ in copper so far. I have a 1500 watt rms amp on a 1-12” dvc 2 olm wired 1 olm amp is happy at 1 giving average 1800 to 2000 max, now also have 3,5 farat cap, do i need a big alternator????? Thanks awesome videos