CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
'78 K10 Build
- Thread starter 78SWB
- Start date
Back to square one. Truck is dead again...
andyblack
Registered Loser
The alternator may have been bad, but I'm telling you - something is draining the battery. It's going to be something like the dome lamp or cigarette lighter. Just do like I said and take out one fuse at a time until you see which circuit it is. 
The alternator may have been bad, but I'm telling you - something is draining the battery. It's going to be something like the dome lamp or cigarette lighter. Just do like I said and take out one fuse at a time until you see which circuit it is.
But those things weren't changed at the time of the engine swap so I don't know how that would effect it. I did change the cig lighter like a year and a half ago. I think it's something in the wire harness from the donor truck not wired correctly.
andyblack
Registered Loser
That very well could be. But things have to go bad at some point you know. I hate wiring issues. What a pain. 
It very well could be I just can't think of what I woulda done differently. What else did we change? Tach light?
Yeah I didn't think about that but the light shuts off when I turn the key off.
The weird thing was the faint buzzing noise that came from the alternator when the power wire was connected.
Yeah one of these day when it ever gets nice again we need to.
The old alt was definitley part of the problem.
Your saying the alternator is still draining the battery? His factory wireing plug has 3 wires to it. Mine only had one and so did my new harness. So I was a little confused on how to wire it?
No, I wrote "was".
Martin
Martin
I'm saying it may still be......if I wired the plug wrong
Possibly, I do not know.
Martin
Martin
andyblack
Registered Loser
I think there's some info on here about how to swap over to a one-wire alternator. It's supposed to be an upgrade from what I understand. Sounds like a good place to start looking. If it were wired incorrectly, the alternator may not have been able to charge the battery, so the battery died and took the alternator with it. I've had that happen before, but it was on a Ford truck with a high amp (140 I think) alternator. A normal 80 or 90 amp one isn't so quick to die from a low voltage level in the battery.
He had been driving it. The alternator is charging.
Martin
Martin
Yeah it's definitley charging, but something is slowly draining it and the cold makes it worse. The alternator wiring sounds like a good place to start.
andyblack
Registered Loser
So how long does the battery take to die when the truck has been parked out in the cold? If it takes like a month, then that could just be the cold weather, but if it only sits for a day or two then it's a slow drain. If you run the engine long enough for the alternator to fully charge the battery, does everything work right? I'm just shooting in the dark here but sometimes talking through things can help figure out the problem.
