dc amps different on different wires

Obviously I am not too savvy on even basic wiring so I might be measuring across the wrong points. But if I put the positive lead from the DMM to the positive wire and the neg lead to the neg wire, I get a negative number when I have DCA 20 selected. I am not too concerned with the polarity from amp to speaker, more so from the stock head unit to the stock amp. I think I have some wires crossed somewhere and it is giving me poor sound. I ran wires straight from my aftermarket amp to each speaker, no breaks or splices. So those should be right. I get the negative DCamps from my stock amp to my LOC. So I think I have the wrong wires from the stock amp to the LOC. Otherwise the stock amp should put out the proper polarity regardless the input to the amp. I did shift all the sound to the front right speaker and all of the reading across the wires from amp to LOC read the same as if all channels were driven evenly.

Again, thank you for your insight!

STOP TRYING TO READ AMPS. You do not want to read amps at all. Plus, audio is AC not DC so any reading you get with a meter selected to DC is meaningless. Just stop trying to use that meter until you know how to use it. What's the DVM make and model?Support the12volt.com

I have a small red DVM. It is made by CEN-TECH item #90899. It may have cost $5 at harbor freight. Since I dont do alot of electrical stuff, I figured I did not need a $50 DMM. Kinda kicking myself now. Please hold the laughing. It has DCV, ACV, DCA, continuity, resistance, hFE, 10A.

The reason I was measuring with the DCA 20m setting was I was not getting a measurable number in DCV, so I assumed amps were the way to go. So I should be in AC volts?

I am sorry if I frustrate you, its just anything I find online is either for complete dummies or electrical engineers. I like to think i am in the middle somewhere.

Thank you!

OK so I reread the whole post. First off, thank you guys for trying to steer me in the right direction. I think I was so set on finding my solution that I did not listen to you guys. I am going to try AC volts tonight and see what readings I get. I just cant tell if I have a very strange situation to start off with or if I made it strange.

Stupid question but here goes...If I take the meter and put the black probe on a good chasis ground then take the red probe to a speaker wire would that tell me polarity or just cause a short? I have a feeling it is a short.

You cannot determine speaker polarity with a meter. I gave you a method in an earlier post.Support the12volt.com

fair enough. thank you for all of your help.

And by the way, to measure the voltage output of an audio amplifier you would use the ACV setting. To measure the voltage from your car's electrical system, you would use the DCV setting. You cannot measure amps (the "A" settings) by placing the meter leads from pos to neg. I recommend you do not attempt to measure amps in any case.Support the12volt.com

Hey Dyohn, I tried the AC volt setting and I didnt get much of a reading. Maybe I did it wrong, maybe the meter wont measure that low of a value. The voltage output of an amplifier would be a positive number right? Unless I had some wires crossed. I will search how to measure the output of an amp.I guess the reason I was measuring DC amps was that they were the only thing that showed any numerical value on my meter.

Thank you for all of your help and especially your patience.

Here's the formula: Power = (voltage times voltage) divided by resistance. So, a 50 watt amplifier when it's at max output, assuming a 4-ohm speaker, will equal about 14 volts AC. A 10-watt amp (such as a vehicle head unit) will give you about 6 volts. Disconnect the HU speaker wires from the LOC, play some music, turn the HU up and measure the voltage across the speaker wires.Support the12volt.com

I appreciate the formula and info. So to clarify, I would use VAC, touch the pos lead to the pos wire and the neg lead to the neg wire and should get a reading of some sorts? Will it be a positive or negative value? Will it be the same value to all pairs of wires (so long as fade and balance are centered)?

Thank you! Have a great Friday!