I have an 04 with an odd electrical problem. The battery drained sitting in the driveway. The odd thing was I could hear an electric clicking noise coming from under the bed that stopped when the key was turned to the acc/run position. Any ideas?

 

Did you have the battery tested? If it's good, maybe a corroded ground. Does the engine even turn over? What you're hearing is probably the fuel pump trying to work, but maybe not enough juice to power every thing.

 

The battery is pretty new and the wires look good. Truck was running great at 8 AM and completly dead at 10 PM when I went to lock it with the key pad. Why would the fuel pump try to run with the key out of the truck?

 

It shouldn't, I misunderstood, I thought it was with the key on. I'd at least get the battery tested, they can have bad cells, or warped lead plate that can short the battery. Also check for the dome light being left on maybe.

 

I'm thinking faulty FPDM creating a draw and draining the battery. Pull out the multimeter and start testing circuits to see where the draw is, load test the battery to check it's not bad, check alternator output, etc. Unhook the negative battery cable and, after setting the multimeter to amps, check for current between the hooked cable and the battery terminal it came off of. About 25mA is normal these days, even up to 60, but if you're up to 100 or more, start pulling fuses until you see the multimeter reading close to 0. Or, measure the voltage drop across the fuses, comparing values of same amp fuses to find the offender. Start with the fuel pump fuse. If the battery drained, though, it may be permanently shot anyway, though.