bazmonaut

I dismembered my oil pressure sender trying to get the big black rubber electrical plug off it. Car is a UK '89 S4.

Does anyone know which wires go on which post on the sender? The wires are contained in a red sheath.

Looking at the posts on the sender as if you were lying on your back under the car - the three posts make a 'face', two eyes (close together - untrustworthy!) and a 'mouth'.

What colour wires go on each eye and the mouth?

Woe is me, three months now with no driving, after a load of problems with a 'routine' fitment of front pads/shocks, then the bugger wouldn't start due to duff LH (now rebuilt by JDS - top job and top bloke), now this. Give me strength.

Many thanks in advance

Barry
'89 S4

Tom in Austin

Sorry to hear that. I'll look at the wiring diagram and see if they identify the pin outs in any way. Are there any letters or numbers on either the sender or the connector?

A possible clue ... in '89 they went to three pins instead of two to add a signal ground required for the dig instr cluster. It's possible that one pin standing apart from the others is this ground. Or said differently, if you happened to have the old two-pin type to compare you might be able to see how it had changed ... but that's just conjecture

bazmonaut

Hi Tom - yes mine's the three pin type. One of the wires is thinner than the other two and in the wiring diagram goes to 'sender ground' - so this must be the one that goes on the 'mouth' post.

The other two wires... I've found them on the wiring diagram but no idea how to work out which is which.

I've a 50% chance of getting it right - but would this experimental approach damage anything?

Barry
'89 S4

Tom in Austin

I think I have good news for you. Of the two non-grounds, one labeled "6" on the diagram is for the "Sender" signal (the gauge) and the other, labeled "WK" is for the "switch". My understanding is that the "switch" signal is for the idiot light. Therefore, I think you could try hooking them both up and see if the gauge works. If so, you have them right. If not, reverse the two wires and then the gauge should work. But probably no harm in having them backward.

Good luck and write back what you find.

Big Dave

It won't damage anything if you have them wrong. You'll know immediately because your oil pressure indicator will flash like crazy, saying "0" pressure.

Happened to me after my rebuild. I just reversed the wires, started it up, and everything was normal. Don't worry about it. Hook it up, test it, and correct them if necessary.

borland

I found that heating this three prong plug with a hair drier softens the rubber plug enough to allow removal. But its still a bear, and much harder than the earlier two connector cars.

Since its a unique molded plug, how do you plan to reattach the wires?

Wonder what a new harness costs?