Fuel gauge wire routing question

[dmack91]

Trying to get the fuel gauge working on my 1983 K20. It was originally a diesel which a P.O. converted to gas. I replaced the butchered dash wiring harness with one from a donor truck.

I traced the wire from the tank valve on the frame. It is pink has been cut off at the base of the firewall near the clutch slave cylinder (with a yellow wire that I believe is the old water sensor wire for the diesel). Can anyone tell me where it physically comes through the firewall and connects to the cluster? Is the wire still pink at that point or tan as the cluster wire is)?

I'm assuming if nothing else, I could pull the cluster again and splice it to the terminal in the cluster plug, but would prefer to find where it actually is connected to get to the cluster plug.

Thanks for any help you can provide.

[ray_mcavoy]

The fuel gauge wire should pass through the firewall via the bulkhead connector behind the fuse box. I believe it's in the same portion of the connector as the engine wiring harness.

For 83, the entire length of the wire was originally pink, all the way from the gauge to the tank. What year truck did your donor dash harness come from? The might explain the wire color difference because GM did use a tan wire for the fuel gauge in the earlier years before changing over to pink sometime around 78, 79, or so.

[dmack91]

Ray, thanks for the info. The donor was an 84. Gauge connector wire is tan according to the diagrams I have found. I thought the 83 was tan also but I will try to confirm that. I traced it to the bulkhead connector on the old 83 harness, so I need to confirm it's I the same spot on the 84.

[gmachinz]

It is in the same spot. Bottom 2 cavities-the one on the LH if viewing the outside of the bulkhead connector.

I attached a general image of a bulkhead for an example-I have several styles based on engine options but as for 1978? to 1986 I believe this is correct. In 1987 with TBI GM moved that sender feed to the rear lighting bulkhead connector. Circuit number 30 is the fuel level sender feed

[dmack91]

Gmachinz, thanks for the help. That confirms what I was able to trace out on my old harness.

Now I need to tap the link sender wire from the Pollack valve into it.

Trying to figure out my Pollack valve now. I have readings at terminal A and C. At first I also had it connecting through to the B terminal, but now I don't. Not sure if I have a bad valve, or if the dash switch could be the problem . I have a spare, used Pollack valve that I may swap in And see if the B terminal shows connected to either the A or C terminal.