Thread: Aftermarket amp issues

Hoping someone else has run into this issue and has a fix.


I have installed an aftermarket 4 channel amp, as well as an aftermarket deck and speakers, no sub. The problem I am having is the amp is going into protect mode because the GM alternators put out 15.5v. The amp goes into protect mode the moment that happens. I see a few youtube videos of Chevy S10's with the same issue, and the fix being unplugging the wire to the alternator. However, 1. Im not sure if that would work with mine, yet. 2. I dont want to deal with the battery light being on, and not actually knowing if my systems is not charging. I tried to see if there were amps on the market that could handle 15+v, but its not easy to find that spec, or if its even made.

I cant be the only one with this issue, and I am looking for the *Correct* fix.


Thanks!

One solution which can't miss is pulling out the aftermarket crap and returning it.

Count your blessings. You could have done this in a Monte Carlo and lost your headlights.

The car is a fun daily driver for me that I spent very little to no money in acquiring. Part of that is I built up a system that I can enjoy while driving or sitting in my car at work. So returning it is not the solution I am looking for. I always look for solutions over giving up. With that being said:

I figured the issue out, and am posting here about it to help anyone else that may come across the issue. TLR at end.

As stated in my intro post, prior to installing the AMP and new speakers, my alternator died and spit some flames out the side, causing me to have to replace it. Thank god for how easily accessible it is. This is when I installed the AMP and speakers all in one go. While doing that, I broke the harness that goes to the alternator. (2 wire harness). Headed to NAPA and purchased the 4 wire plug to splice in. Well, in my haste, I did not crimp one of the wire well enough causing it to come loose in the butt connector. Which was what was throwing my battery light making me believe I purchased a bad alternator. I found this out when I replaced the alternator again and the wire fell out of the connector. Correcting my careless crimp took care of the battery light. However, I was peaking at 15.5V, causing my AMP to go into protect.

After a lot of back and forth with the AMP manufacturers, I thought I was done for. Both AMP manufacturers told me it sounded like I had a bad PCM that was telling the alternator to spit out that voltage. After a few days, I had an epiphany. I disconnected my battery to rewire my amp 12v lead to the battery and not the fuse box post. I walked away for awhile when I was having trouble hooking it to the side post. I returned and hooked the battery back up with my lead wire back on the fuse box post. Voila! Normalized voltage peaking at 14.3 with an average of 13.7. What I assume, or just got lucky was that with all the alternator issues I had, the PCM adjusted to those issues, causing the 15.5V average. Not sure why, but it is what it is. I am assuming with me disrupting the power to the vehicle by removing the battery, it reset the PCM. Amp now works flawless, and it even solved an issue I had with my backup cam having waves through it.

This is why I did not want to just "give up, and return it." This car is a daily driving toy for me. A car that I always wanted when I was younger, and fixing it is actually quite easy compared to todays newer vehicles... And cheaper. The car is a lot of fun to drive, even stock, and now I have an amazing entertainment system in it. Half my day is spent sitting in my car after my main duties, and my secondary job as a private investigator is 95% sitting in the car. I now have an Android deck that runs netflix and amplified speakers with virtual surround sound. Its like sitting in a movie theatre.

TL;DR -
Check that the alternator is performing correctly
Check the 2 wire harness on the alternator
Disconnect the battery for a few minutes and reconnect it. Especially if one of the 2 above was an issue. Assuming this reset the PCM to "re-learn"