Bros1929

I have quite the interesting problem that has been causing me headaches ever since I discovered it. On my aftermaket audio system in a 2001 GLE the subwoofer amp will go into protection mode for a second or two after a few short, hard bass notes when I crank the volume. I have a voltmeter that is telling me the voltage goes down when the bass hits, as it should, but instead of returning to ~14.5V it will jump up to +15V even as high as 15.5V. This only seems to occur when I am going over 40mph which leads me to believe the alternator is overcharging the system when the bass stops and the voltage spikes and puts the amp into protect mode as a result. I dont think anything is overheating as it has happened on subzero days minutes after starting the car as well as hours into drives on hot days. I checked all the fuses, connections, wires, and ground points and everything seems fine. I am running a Rockford Fosgate Prime R750-1D mated to a Rockford Fosgate P3-1X12. The alternator is not stock, I believe it is the upgraded 150 amp model but I cant say for sure since I replaced it over 2 years ago. The battery is only about a year old. Interestingly, this problem only started after doing the big 3. I have not ran into any other electrical problems other than dimming dash lights, but I'm keeping my fingers crossed. The video was taken about 3 hours in on my trek downstate, excuse the song choice it just seems to illustrate the problem the best. Any help is greatly appreciated!

***VOLUME WARNING***

Bros1929

I forgot to mention I am running a Pioneer 400 watt 4 channel amp that is wired to the same distribution block as the sub amp. What baffles me is that both amps are receiving the same voltage, but only the sub amp goes into protect mode. Maybe the pioneer over voltage protection threshold is not as severe as the RF.