strange electrical issue

[jorensmith23 10+ year member]

I have a car that's had a system in it for months with everything working fine. One day the sub woofers both stopped working. I immediately did a process of elimination.

All fuses are fine.

The grounds are fine.

Tried a different amplifier.

Tried a different CD deck.

Tried different sub woofers.

Used my meter to check if the power was making it to the amplifier which it is, and both amplifiers I used both came on, however both of them have nothing coming out of them to go to the subs.

I just cant seem to figure out the issue because I would have thought for sure it was the amplifier that was having an internal issue but after trying a different one as well as with a different CD deck that are both working just fine in my other car still gave the same exact problem. There is also power coming from the cable that runs from the CD deck to the amplifier, and have even tried to replace the RCA cable as well.

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[Falcons 5,000+ posts]

Wires shot?

 

[ahole-ic]

It sounds like your rca's came unplugged OR the rca out was blown on your deck because your ground IS NOT good at the amp, causing the amp to draw current across the rca's thus killing the HU rca outs.

 

[keep_hope_alive Premium Member]

Use a DMM to measure VAC output from amp. If yes, use DMM to measure continuity between sub wires at amp and at sub. Some box terminals will melt and fail.

 

[jorensmith23 10+ year member]

I know it cant be the cd deck's rca out is not blown nor the amplifiers because i used a different cd deck and amplifier that works in one car but not this one, i even changed the plug ins that go into the cd deck to see if maybe one of them broke on the inside AND tried running a different cable that goes to your cd deck to your amplifier, the only thing i can even think to next is try to wire a new rca because maybe the cable itself burnt out on in inside. I know its not the subwoofers because i tried other ones that still worked and have already checked to see if there was even any power coming out of the amplifier and its not. It's getting the power into it, turning it on, but isn't giving the power out to the subwoofers, i thought for sure that that must have meant the internal fuse to my amplifier is blown but i know that can't be it because i used my other amplifier in my other car that works and it gave the exact same issue and same readings with my meter. I have 0 gauge grounds, and they ARE good, i drilled into the framing of the car, made sure to have no paint on it at all, its pure metal to metal and they are all cleaned and on very tight. Ive worked on a lot of car systems and i know what all the common problems are that happen and know to check that ****, but this honestly is just the weirdest thing ive ever seen go wrong in a system. If anyones got more ideas besides trying to replace the rca cable, then please share your knowledge.

 

[keep_hope_alive Premium Member]

use a DMM and measure continuity on wires to determine if they are good, measure resistance to look for shorts, measure VAC to determine output. without a DMM you can't troubleshoot.