Help Please...Volume dropping and distorting...
 

Hi. I have pretty low end equipment but it sounds pretty good to me. I have a 50watt/channel Dual XPE2700 powering my door speakers (6 x 9) and dash speakers (5 1/4"). I have another 50 watt/channel amp (Soundstorm) powering my back 6 x 9 and tweeters. I also have an MTX 8" subtube. All amps are individually wired from the battery with 8 gauge wire and grounded with the same. I cannot say for certain that I have perfect grounding but have sanded away the paint and bolted to what seems like good grounding points - bolts I found along the sliding door tracks of my van.

Here is my problem and volume level has no bearing on what happens. Whenever my radiator electric fan comes on, my sound drops and gets distorted. It only lasts a second. If I run the stereo with the engine off I have no problem.

I don't think that my system draws that much power but I am afraid that I might damage my amps. If it is causing a sound drop and distortion briefly and occasionally, am I likely to suffer damage? If I am running say on the highway at 2000 t0 2300rpm, it doesn't happen. I'm pretty sure I will have to upgrade my wiring or battery or alternator or make my grounds better, but am I at risk of amp damage in the meantime?

Also, I don't crank my system that high but the amps are barely warm to the touch even after an hour or two of playing.

Thanks in advance for any help and advice.