Cab harness questions/issues

[dmac2590]

I swapped a cab on my 77 k15 for an 80 c10 cab. I plugged the engine harness in and the only power I have to the entire cab is the 4 way flashers. I've pulled every fuse in the think and checked they're all dead. Any one had this happen to them? Stock swap 350 carb engine not an LS swap. Thank you all.

 

[TotalyHucked]

You'll need to search for the wiring diagrams for each truck. Being 3 years apart and probably different trim levels/different option packages, you'll need to figure out what each truck had to start with and how to adapt the harnesses together.

 

[dmac2590]

I was afraid of that. I might just swap tge old harness back in and give it a go.

 

[Doppleganger]

Sounds like a main feed to the fuse block. Can you use a DVOM and start back tracking where current is and isn't? With the whole thing going away, I would imagine you solve one issue and you'll solve them all. '

How are the grounds? "Updated" harnesses can have a tendency to change where and how things are grounded too.

 

[dmac2590]

The truck was rough when I recieved it but everything worked fine-ish, lol. I have power at the battery, starter, alternator, and junction block. Tried to stab my volt meter in the back of the wire feeding the fuse block and got 12v there. The flashers work and I have 12v to an auxiliary that is it. I had redone a body ground quickly to see if thats the issue it didn't change a thing. The cab is the same as the set up at the old cab just glass fuse to blade fuse and some of them are in different locations. If I can avoid swapping the harnesses that's my game plan.

 

[Doppleganger]

You have 12v at the fuse block but nothing at the individual fuses? Could the block itself be defective? I'd try a continuity test between the main and one side of the fuses.

 

[dmac2590]

Only 2 of the fuses have individual power. The flashers and an auxiliary power port. I'm not sure about the block itself. I'll pull the harness from the firewall and ohm some of the connections.

 

[gmbellew]

I'd be comparing some wiring diagrams. seems to me the odds of things lining up in the right spot from a glass fuse panel to a blade fuse panel are probably low. you can probably make it work, but will take some rebuilding of the harness connectors.

 

[dmac2590]

Yeah, 12v at the fuse block. I'm going to do all my body grounds I might have one that's funky. I know the connections are clean but something could be hindering the ground. I'll also do a ohms check on the block while I'm at it.