Key Off Drain

[ChillWinstonC20]

So I've poured over this forum and there is lots of good information but there is no cure for stupid anywhere that I can see. So I'll post this even though others have posted others like it.

Seriously, I have a 72 C20. I've got a key-off drain happening. I pulled the negative battery cable off and connected my test lamp. When I complete the circuit, it stays lit all the time. I pulled every fuse and the light stayed on. I pulled the in-line fuse in the aftermarket radio line. I pulled the dome lamp bulb. There was something mentioned about testing the alternator in one post - I tried pulling that off. I pulled the battery and had it tested. They said it's fine. I checked the key-off items that were mentioned - checked the horn and it seems OK. The headlights work as they should. I have not been able to find a way to get that test lamp to shut off.

Two notes that may or may not be related to this:
I did a number of repairs around the time this started happening. I replaced my distributor and added an external coil. I found several wires disconnected or broken while putting things back together, two of which I can't figure out where they go based on wiring diagrams. But most things work... other than the drain.

I replaced the dash gauge cluster "wiring" and attempted to upgrade to LEDs in the gauge cluster. This was not 100% successful as some work and some don't. I have not figured out why this is.

I would appreciate any help/insight/comments. I've read about installing kill switches or inline resistors and I won't rule that out but I'm most interested in figuring out what's causing this to happen and hopefully attacking the root issue. Maybe we're back to the stupid thing...

[panhandler62]

You should be able to eliminate a couple things fairly quickly.

From the (+) terminal you have 2 leads. One goes to the starter and the other to the junction block.

From the junction block you have one wire going to the alternator and one going to the fuse box.

If you isolate the smaller wire from the junction box (going to the fuse box) and you still have current then the problem is not in the chassis/cab wiring.

Leaving that off; disconnect the fusible link from the junction box. You are now only completing the circuit through the starter. Only the starting system should be active.

You've attacked a lot of things at once here (and probably fixed problems you didn't even know you had!) so it would help to narrow the field to find the gremlin.

[ChillWinstonC20]

Thanks! That's great advice and a reasonable approach to take. I'll let you know what I find based on that. And with advice like this, I just might overcome my personal deficiencies...

[67 Burb]

Originally Posted by ChillWinstonC20

I replaced the dash gauge cluster "wiring" and attempted to upgrade to LEDs in the gauge cluster. This was not 100% successful as some work and some don't. I have not figured out why this is.

To address the LED problem:

LED's have to be plugged into the socket with the polarity correct. Any LED that doesn't work, just unplug it, give it half a turn, and plug it back in.

Bob

[ChillWinstonC20]

Beautiful. I'll give that a shot. Thank you.