linderpat wrote: ↑Wed Sep 21, 2022 5:15 am
Using the multimeter at the jump post, which pin is it? Also, which fuse panel slot for the sender?
To your question: Pin 4 on the jump post connector is for the OP Gauge. It is a resistance circuit to the cluster. Ground is the sender connection to the block. No fuse.
In my experience, wonky, wobbly, jumpy OP is always front main engine harness wiring at the sender. Any past service of alternator or pan gasket results in a non-zero probability that a not-careful or trying-to-do-the-job-as-fast-as-possible "technician" damaged the wiring at the sender. Also, oil pan gasket leaks result in that part of the harness soaking up oil which, over the years, will damage the conductor insulation.
Start there. Under the car. At the sender. Very carefully pull back the boots on the sender connection and examine the wiring to the sender. Gauge wire is blue with a white strip. Idiot light wire is blue with a black stripe. Those colors would have faded towards "motor oil" color over the years.
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