Voltage drop test, ground and power

[butterMilk 10+ year member]

Can anyone explain exactly how to do a voltage drop test on my amp grounds and power.

So I set the DMM to DCV, 20. section?

Then I had jumper cable on the ground of my battery and ran them back to my amp, touched one lead of the DMM to the jumper cable and the other to the ground on the amp itself, what numbers am I looking for at this point?

Do I do the same procedure for the positive wire? Then again what numbers am I looking for?

Am I going about this the right way? I want to ensure I have good grounds, and good power wires. I have read that a resistance test is not as accurate. I tried searching but didn't come up with much.

Thanks for any help!

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[goingdef 10+ year member]

I have never heard of testing like that I would think it's very inaccurate, I just read the battery and then read the amp terminals perfect setup would see no difference from one to the other.

 

[raptor727 10+ year member]

Just run positive to positive and negative to negative on the amp and play either one of your hardest hitting songs or some sine waves and see if it drops below 12.5 f it does you either need a ho alt or more battery power thats just my way though others may say different

 

[butterMilk 10+ year member]

Thanks guys!

What about for checking if you have a solid ground? Something other than the ohm resistance test?

 

[maylar 10+ year member]

What you're looking for is the difference between the battery voltage and what appears at your amp. Unfortunately you can't check them both at the same time unless you have 2 meters. As mentioned above, you want to play the loudest heavy bass music in your collection so the amp is drawing maximum current. Check the battery voltage at the terminals and again at the terminals of the amp. Ideally they should be exactly the same, certainly within 1/2 volt (battery will be higher). Thing is though with music you don't get steady current draw so it's tough to get a reading.

 

[butterMilk 10+ year member]

So would you recommend using test tones?

 

[Below20hzonly 10+ year member]

yes

 

[maylar 10+ year member]

No. Test tones at full power will likely hurt the sub(s).

 

[tc300 10+ year member]

Just start at a low volume and work your way up to you see voltage drop......