Running lights, tail lights and dash lights not working

[87gmc512]

I have a 87 gmc short bed and after I installed a new radio my lights aren't working. Break lights and head lights still work but when I pull the light switch the T/I fuse blows.. ive traced all the wires from the front to the back to under the dash,switch and instrument cluster everything seems fine. Also when I turn my head lights on my dome light stays on (but dim) and my floor board light stays on also. I know it's something so simple that I can't find and I would hate to pay a shop to do it for me. So PLEASE SOMEONE HELP

 

[bucket]

Did you wire the radio direct or with a plug adapter? If you used an adapter, unplug your new radio and see if the problem goes away. Does the radio have a separate "dimmer" wire?

 

[87gmc512]

Lol that's exactly what it was. My buddy wired the radio up and had the brown dimmer wire grounded. 3 days of tracing all the wires and it was in my face the whole time