I have a 2004 gmc sierra. When I first got the vehicle it already had an aftermarket duel head unit in it. I tried to turn it on and my check engine light went off and my abs battery lights came on and windows wouldn’t roll up or down, I turned the radio off and a few minutes later after turning car off and back on everythjng worked fine. It happens every time I turn on radio…any suggestions? Next. I have had my ac drain plug cleared of debris and I still get water I n my floor board. I was told it might be a heater core but then redirected after I informed the person it only happens when my ac is on not when its off can some one please tell me what I can do to fix it its not coolant just water doesn’t leak when it rains only when ac is on…
Maybe you could spray the windshield with water and see if its coming from there.Also,check the floorboard for rust holes.
I would suggest there is a leak in your AC air handling system - the airbox that collects the condesate water. While some goes down the drain, some goes onto your floor. A flashlight and some talcum powder may help you find the leak. The talc lets you find the drip from the airbox.
As for your radio issue… clearly the radio is causing this. Either live with it or replace the head unit.
If the AC air box isn’t leaking then the water may be from condensation forming on the outside of the box. If that is the case you may have to insulate the box.
The radio issue sounds like there may be a wiring problem with the installation. Perhaps a grounding issue. I would go over the power and ground connections to the entertainment system and verify the connections to the car wiring.