wildwestsydney

Hi 1984 928 euro 5spd. Car came with replacement alternator but not insalled. I removed the one that was in the car had it checked and it was bad so i am installing the new rebuilt one. The alternator that came out had three wires connected to it. I suspect that it should only have two. The oil pressure sender only had one wire connected to it. The wire harness has a breakout with two wires going thru the big rubber grommet / seal that get contained by the alternator shroud. the othe two wires break out before the big rubber grommet. One of these was connected to the oil pressure send the other was connected to a blade connection on the back of the alternator. The car had no alternator shroud on it when I got it so I suspect that the person that had installed the alternator thought that three wire get connected to the alternator. Am I correct to think that the blade type connector should go to the oil pressure sender and only two wires go to the alternator?

thanks

Alan

There is only one small wire to the alternator + 2 large ones that go to the same B+ terminal.

You should have 2 wire connections to the oil pressure sender/switch (the case also directly grounds to the block)

Alan

wildwestsydney

thanks the new rebuilt alternator is working great. I am not sure what the person was thinking to connect the oil pressure sender wire to the alternator.

On a side note my oil pressure has alway been maxed at 5 it still is with the wire connected to where it should be. I can tap the instrument cluster and get a true reading for a few seconds but then it just maxes out again. I also have the MPG gage and that is very erratic. I am not ready to tackle these issues yet but if I can get some advice ahead of time that would be great.

tailpipe

try switching the wires around on the ops it only works in one direction the wronge way maxes the guage

surfdog4

About the gauge, have you pulled the instrument cluster at all? I had all sorts of gauge problems (inclulding a pegged oil pressure gauge, speedometer that only went to 35mph, jumping voltmeter) so I pulled the cluster and basically rewired the connectors..The flexible circuit board back there is flimsy and prone to corrosion..after i reworked it (and fixed the odometer gear) it works great. You might be able to just clean up the contacts, but i would look there before i go to far troubleshooting