No turn signals or interior lights

[77Lew]

I just bought a 77 k5, I got it pretty cheap and it ran good, but the only gauges that worked were speedometer and oil pressure, got it home and found that traces on the back of cluster were rotted, and I had no interior lights or turn signals, and my hazards worked but were fast and dim, I figured this was all linked. I ordered a new board from lmc, installed it, still no signals, still no interior lights, but my voltage gauge works now, still no temp or gas gauge though. Any ideas where to go next? I'm thinking headlight switch because as I said I have no interior lights at all and I've replaced them all while I had the gauge cluster out, doesn't matter where I set it for no lights on the dash, or domes either one, and I'm wondering about the signal switch too, and sending units on coolant and fuel gauges. Also I've checked all the fuses, and swapped the 2 relays, with no change. Really appreciate any help on this if anyone has ran into something similar. The guy I bought it from bubble gun and s uperglued everything in the interior. But I got it 2 hrs from home, and drove it the whole way without issue for $1000, so I didn't think I got hurt too bad.

 

[4xfrankie]

The test light,multi meter, and wiring scematics are your friends!lol

 

[77Lew]

That was my next thing, I've just been changing stuff that I either knew was bad, or was cheap and wouldn't hurt to change. I don't have anywhere heated to work on it and it's been highs in the low 20s here for the last week, so I was hopin maybe someone could steer me in the right direction like maybe they'd ran into it before.

 

[4xfrankie]

No popped fuses , and no open circuits? Might be a bad ground. I will look at wiring diagrams for 77 to see if any of the circuit's are connected.Is the temp gauge wire connected to the sending unit on the head good ?Is the gas guage needle showing past full?Could be a bad ground at the gas gauge,or a bad sending unit in the gas tank.Keep us posted.

 

[Carcinogen]

what is the gas gauge doing / where is the needle sitting? All the way empty or past full? This might give you an idea of open circuit or short to ground on that circuit at least.

 

[77Lew]

Way past full

 

[Carcinogen]

Try pulling it from the sending unit and grounding it out. That should move it to empty. If so, that means your gauge working properly and the wiring between sending unit and gauge are good. That also means you have a bad ground on your sending unit or its broken

 

[77Lew]

Alright, thanks guys i appreciate it, ill give it a shot as soon as i decide to brave the cold and snow