A few months ago, I had a place put in a new system in my 05 Sierra.
After listening to it relatively loud for a while, the volt meter dips. It's usually around 14.2-14.5, then after about 10-15 mins it dips down to and stays at about 12.0-12.3. If I turn off the system, it still stays down there. The system is by no stretch of the imagination big.
It's just a Kenwood Excelon HU, KW 70x4 amp power front and rear speakers and a Kicker 100x2 powering a little JLAudio 10" sub. There is a 1 farad capacitor in the system, but I don't think that's doing much of anything other than showing some cool blue and red lights.
Could the dip in volts mean the signal is getting choked from the battery? Alt? Anyone have some suggestions on what to try to fix it?
Thanks!
Steve

 

upgrade the main wires under the hood. any time you present a heavy load, your voltage will dip. like when you turn your AC on. if by chance, the wire from your alt to battery is getting hot from heavy charging, resistance in it will go up. that would be why your voltage is staying low after you turn you stereo off.

could also be alternator voltage regulator issues. but i'd tackle the "big 3" wire upgrade first.

 

[QUOTE=95stroked1500]upgrade the main wires under the hood. any time you present a heavy load, your voltage will dip. like when you turn your AC on. if by chance, the wire from your alt to battery is getting hot from heavy charging, resistance in it will go up. that would be why your voltage is staying low after you turn you stereo off.

QUOTE]
He has less than 700 watts. I am running 1375 watts and I just upgraded to a 145 amp alternator with all stock wires under my hood with no problems. Unless he has some faulty wires from the factory.
Did they run one 4 gauge or two 10 gauge to your amps? Make sure the grounds are good, and SHORT in length.
I would have the shop check the capacitor, make sure they charged it all the way up. Then take you alternator and battery off and have some one test them. Its free. I know your truck is an 05 but I would still have them checked.

 

Thanks both of you!
Blue - I'm not sure what they ran. I will check at lunch though. I'll also check after work about where the grounds are.
In another possibly related/unrelated issue, driving in to work the other day, while waiting to merge into traffic, the truck just died. Stereo wasn't loud, no a/c or anything else on. Put it in park, cranked it, and it started right up. Hasn't happened before or since. I might have another stereo place go over everything this other place did to check their work(if I can find a place that'll do this). I've taken this system back to the installer 4 times regarding an issue with the volume dropping out(like thermal protection) after playing loud for a while. They just added crap until it stopped(capacitor, 2nd amp for the sub), now the volt drop problem. And this place competes in competitions.

 

Did they put a remote start or an alarm in your truck?

 

No. They hooked up the steering wheel controls to the new HU though.
I didn't get a chance to check out the wiring at lunch. Work lunches bite. Grrrr...

 

i saw his wattage rating. still doesn't hurt to upgrade the wires. especially yours blue 01. you can get away with what you have. look at even the 4 ga rating, suggested not to exceed 120 amps. i know, it's done all the time without problems. people with voltage probs (if it's stereo caused), upgrade wires first. that's where i start anyway. even if the shop didn't "precharge" the cap slowly, it would charge as soon as it was connected to the battery.

leave your alternator and battery in. those are just as easily tested in the vehicle without the trouble of out and back in.

another problem i've seen is a short or break in the battery. i've seen them where you get a 12v reading testing with a meter, but because of the internal brake, once you try to flow any amount of current across the crack, the voltage drops to about nothing. can hit a bump work fine, hit a bump not work.