System issue...help

[MarAha 0]

A few weeks ago, I noticed my sub randomly get quiet and loud back and forth ONLY while driving. When I'm at a red light or stopped for any reason, it plays a lot quieter than it should be (literally half the volume that it is when it's loud). When I accelerate, it goes back to normal temporarily. For a few days, it did the opposite. When I braked, it got loud, and when I accelerated it got quiet.

This has been driving my crazy. I checked my wire connections at my amp and they were fine. I had autozone check my battery and alternator and they were good. I even checked the voltage myself on my battery and it was fine. They are both stock by the way.

1 more thing I noticed yesterday is my lights dimmed when I rolled up my power windows. It never did this before. I tried it again today and it did the same thing but didn't dim as much.

Does this sound like it could be an amp problem to anybody? I can't figure it out.

[Julian 641]

Do this for us

Measure your voltage with a DMM at the alt

at the front battery

and in the back

all while idling also.

tell us what you get after that

Edited September 13, 2009 by Julian

[MarAha 0]

Do this for us

Measure your voltage with a DMM at the alt

at the front battery

and in the back

all while idling also.

tell us what you get after that

Few days ago I tested it at the battery with my car on and off:

Off = 12.45v

On = 14.73v

Bass on full blast playing Jeezy - Hypnotize with car on = around 13.04v average

I didn't check it at the amp or the alternator yet. Do I use the same setting on the dmm meter that I used at the battery? And can you explain real quick how to do that (black to what, red to what)? Should I also be doing this with my bass at full blast?

[Julian 641]

Just do it with your stereo off, on your alternator there should be a boot covering a post where your alt puts out + current, and then touch your - terminal of your DMM to the chassis since it is ground, then check your battery so plus to plus and then negative to negative.