WTF. Just returned from a weekend camp trip with our trailer. Got home, shut truck (2003 Duramax Crew Cab) down to unload gear. Started truck up to move the trailer, and as soon as I put it in Drive, the truck shut down. Found the 1B IGN 40A fuse blown. Pulled the 40A fuse from the "Blower" and as soon as I touched the terminals, it popped; even with keys out, ignition off. Put Amp meter on and it shows high amps even though the truck is off with no keys in ignition.

Love this truck, but this is the 3rd time it's been loaded onto a tow truck, heading to dealer again.

Any help or advice would be appreciated. Thanks.

Sounds like a dead short which is much easier to find. Do you have any aftermarket electrical accessories?

The only accessory used is a Belkin IPOD holder/reciever thing that plugs into the cig lighter. This has been used for 6 months now, can't see this causing the issue though.

No it shouldn't.

Dealer just called. The Parking Brake was rubbing on the main harness and wore through insulation, causing short. Not so bad, but thought I'd let others know of potential problem.

Ouch. Another thing on my list of stuff to look out for. What year truck?