vanster

I just tested the sender next to the oil filter and although the wires were not very tight, in fact one fell off when I barely touched it. Cleaned it, re connected it and the gauge is still stuck on the bottom. Time to pull the cluster off.

MainePorsche

Check 14 pin connector now. I believe it is Pin 2 Blue/Black and/or Pin 4 Blue/White.
Someone should confirm.

davek9

I'm not sure on his year, the Pin outs do change some from year to year

MainePorsche

That should be the correct pins for his MY 80.
I would feel more comfortable if this was confirmed for him.

Randy V

Be verrrry careful when tightening the connections to the sender unit.

Those posts are hollow and can easily break if overtorqued.

I learned that one the hard way.

depami

Open circuit is max pressure. Grounded circuit is min pressure.

Disconnect the wires from the sender and start the car. It should read max PSI and light should be off.

Ground both sender wires and start car. Pressure should be at zero and light should be on.

If above is true, sender is bad. If above is false, problem is in wiring or dash pod.