I have a CEL light on my 04 Silverado, but cannot diagnose because the fuse for the cig lighter/OBDII connection blows as soon as I put a new one in, with everything powered off on the truck. Just wondering if this is a common problem with a known solution or if I am going to have to take it somewhere. Thanks in advance.

 

Assuming you have removed the cig lighter from the socket, the socket itself it probably damaged causing a short to ground. I've even seen sockets with a penny stuck in them causing a short to ground. Next step is to unplug the connector on the socket. This will be for the left socket. The right one is on a different circuit.

 

Thanks, I will try that tomorrow when I get home from work. I am clueless when it comes to electrical issues, mechanical I can hold my own, but eff electrical...