Wiring problem in 2004 GMC Envoy

I have a 2004 GMC Envoy and everytime i hit the power windows my lights dim, my truck makes a funny ass noise when i turn it on, my clock occasionaly resets(and gets really hot at times), my 12 volt plug things dont work(Cigarette lighter works fine, but the rest dont work at all) and my back windshield wiper goes off every now and then. Now at the moment, I have no aftermarket equipment hooked up to it, but i previously did. The only thing that I could think that would cause any of this, is I had to hook up a line converter to the back of my factory head unit and had to splice some wires. But when I removed it, i electric taped em together. Also I pulled my power wire through the firewall with the rest of the wires and it was a tight squeeze, but i dont know how it would mess anything else up. My vehicle is currently under warrenty and I took it to the dealership and they said that they fixed it, but later that night my radio reseted and all my interior lights went off for a few seconds(it was night time). Anyone got any idea of what might be causing this?

If it is still under warranty then you shouldn't mess with it any more and just take it back to the dealership. Anything you do could make it worse. As far as what could be going wrong, everything that you mention is bcm controlled and it could be the problem. When you went through the firewall, did you drill or did you pull the wire through an open grommet? Also make sure that the battery terminals are on tight.Certified Security Specialist

Always check info with a digital multimeter.

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BCM= Body Control Module. It controls all the interior functions like the radio and lights.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.