We had a workday north of Baltimore the last week in October, and I was lucky enough to have about five sets of hands helping diagnose my fuel sender issue. What we were able to sort out is as follows:
- My wiring loom up to the bulkhead is not original, but contains original green wiring.
- The ground spade on the sender wasn’t connected (it must have come off at some point after we installed it) but it is now.
- The sender is working properly. We tested it for resistance and it works when we slosh fuel around in the tank.
- The PO put in a grounding wire directly to the frame, which I cleaned up with some sandpaper.
- The wire going up to the bulkhead connector works.
- The bulkhead connector is a mess, and has been screwed with quite a bit.
- Everything behind the dash is a mystery.
The service manual says we’re looking for wire 36-16, which checks out behind the dash but the wire going from the sender through the loom looks like 11. Additionally, the 11 loop (the one which appears to ground on a stud welded to the backside of the dashboard) was loose, so I reconnected that.
While I was there, I bought a Thermoquad from Jason H. for tinkering (it’s the one on the left; the one on the right will get rebuilt as my spare).