What does 90987- 01003 / 056700-4800 control? It's the relay in the fuse box in the cab. I have a issue with my battery dying and when I hook the battery p from charging the relay is clicking.

 

Are you putting the Battery on the charger because it won't hold a charge or is unable to crank the truck clicking relays are usually I sign of a bad battery or one that cannot supply enough cranking amps and voltage at the same time ..or dirty or poorly connected terminals

 

The round one right above all the fuses controls your corner lights and rear parking lights.I don't see this affecting your battery.If you mean when you disconnect the battery post with the engine on and it dies that would be your alternator.

 

I charge the battery over night. The truck then starts up fine. But when I let it set over night it dies.

Whenever I hook the battery back up after it being charged that one relay clicks as soon as the positive is hooked back up and the batt is fully charged.

 

Sounds like you may have a bad diode inside the alternator . Draining the battery Charge up the battery disconnect the alternator main feed wire or all wires to alt .dont let the hot lead touch metal tape it up See if you get a click . Or put charged battery in over night let it sit with alt disconnected and see if ya have juice in the morning ..

Multi meter is a great tool for this . If you have one set t to amps and prob things like starter and alternator fuse slots . Things like starters can were out and pull voltage while off and drain the battery sounds like its a pretty big parasitic drag . If it kills the battery in one night If you spot high amps anything over 3.0 with the car off maybe looking at a short ..kinda leaning towards bad alternator ... Examine the fuse box and under it for for burned or frayed wires ..

 

Thanks for the opinion I"ll check it out. I have the gm alt conversion on he truck. So it very well could be the alt.

 

You was right scrub88. I changed the alt out with a new one and haven't had a prob since. Thanks for the help

 

Good deal man . Glad it worked out. Make sure or check all your power supply and grounds and replace with thick nice new ones if they look worn out .. Amp power wire makes a good replacement in need be