DTC 81
The TCM commands the solenoid “ON” and voltage remains high.
The TCM commands the solenoid “OFF” and voltage remains low.
All conditions are met for 2 seconds.
Commanding on and off is done through the negative side of the solenoid circuit in the computer.
Where I am...
A hot wire is shorting to the fuel shut off solenoid and I am willing to bet you that it aint coming from the ign switch.
Turn the key on but don't start the truck. Check for voltage and amperage at the fuel shut off solenoid.
Shut off ign key. Recheck volts and amps. Are they the same? Some...
From my experience every time a battery post melts it is because the connection at the battery was loose. I have seen quite a few amps flow through a battery post without a problem when they are tight.
One arc from a loose terminal means melting if the amps are passing through.
Pin E is in the middle. Pin A is in the upper left. Ohms should be in the neighborhood of 20.
Like Bison said you can rig a battery and actually check it. A click can be heard.
If the circuit is failing there is a chance that it could be the solenoid or the wiring through the passthrough...