HU overheats?

A friend of mine just bought a used S-10 and it came with a pioneer HU. He keeps sayign that after awhile it will stop playing CDs and says HEAT on the display and won't do anything for about 35 minutes. I don't have the model number but with just that info is there any way to make a diagnosis of the problem? 2 Diamond Audio D3 12s

Hifonics ZXi1006 amp

MB quarts all around and a Panasonic up front.        You wanted to know don't lie...

Heat is a natural byproduct of power. The longer you play something, the more heat that is generated. The louder you play something, the more heat that there is generated. Combine these two factors and you are asking for problems, especially on a hot day in a dark colored vehicle. The issue is simple, the thing is trying to cook itself to death and the protection circuit is shutting it down. I'm going to assume that you are using the built in amp to run front and rear speakers? Turn down the volume, let the thing cool down every now and then, or cut a big hole in the top of the dash for all the trapped hot air to escape.Top Secret, I can tell you but then my wife will kill me.

I would cut the hole in the dash and post some pictures too...