shmkr
Both wires connected to the back of the ammeter will be powered all the time. Both terminals have a direct connection with the battery...the ammeter is the main conduit for current flow in the charging system.
If your battery is discharged and you start the engine, the generator or alternator will attempt to re-charge the battery, which is done through the wiring at the ammeter. If the wires get hot or warm, this would indicate a large current flow, but your ammeter should show this. I would think for the wires to be 'hot' the needle must be pegged for sometime.
This isn't normal, obviously. I would disconnect the battery and make sure the connections on the back of the ammeter were clean and very tight. I don't know what kind of truck you have, but if it's an old Stovebolt, there are not many things that are not switched with the key that could be draining the battery.
A battery plate can short internally and cause the battery to discharge, or something in the horn circuit could be going to ground through a high resistance...this circuit isn't switched.
Check and clean your cables and connections, do a voltage test on the battery before you start the rig, then one when it is running and charging.
Watching the ammeter should tell you if things are going nuts or not. There can't be mass amounts of heat generated (usually) without large current flows.
Do some more detective work and let us know what develops.
Stuart
