1988 3.2 Carrera drivetrain wiring harness questions

[BottleNose]

1988 3.2 Carrera drivetrain wiring issues

I bought my 1988 Carrera with the entire drivetrain missing. I bought another drivetrain from a 1988 (3.2 with G50) and installed it, but I’m having a hard time figuring out where all the wires go since I did not remove the drivetrain myself. I think some of the wire harness might be missing.

Problem 1: The oil pressure sending unit and the temp sensor (on the oil fed tensioner lines) have no wires nearby to hook up to them. Where do wires for these tie into the engine compartment wiring harness?



Problem 2: Where does the wire to the reverse light switch on the G50 transmission come from? I thought it was in the same harness as the starter wires.



Problem 3: There is a six wire connector at the rear fuse/relay block. There is no relay for it to plug into that I can see...am I missing a relay?




Problem 4: Near the above is a female 3 wire round connector...no male for it that I can find.



Problem 5: On the opposite side by the oil filter is a very similar 3 wire female with no male counterpart.



Thanks for you help...ready to get this thing back on the road!

[Flat6pac]

The temp and pressure wire come across the top of the fan in the specific harness from the main 14 plug in harness on the left. Breaks off the harness near the distributor over the fan.
Your oil press sender is not correct Carrera. It should be a brass point sticking up for a plastic connector. That looks more like a C2 sender
The second pic is the back up light switch. Wires come in with the starter harness block coming through the right front sheet metal
The six I don’t recognize in that position It looks like an SC CD plug but must go in the open relay spot.
I don’t recognize the round connectors they look like oxygen sensor connectors but are too far to the rear on the left and don’t belong near the oil filter and tank.
Good luck,
Bruce

[BottleNose]

Originally Posted by Flat6pac

The temp and pressure wire come across the top of the fan in the specific harness from the main 14 plug in harness on the left. Breaks off the harness near the distributor over the fan.

Found it! Thanks for the tip.

Originally Posted by Flat6pac

I don’t recognize the round connectors they look like oxygen sensor connectors but are too far to the rear on the left and don’t belong near the oil filter and tank.
Good luck,
Bruce

This makes sense for 02 sensor connectors...my engine was last in a race car which ran open headers. The one by the oil filter is long enough to go to the back corner like the other side. Did '88 Carreras have two 02 sensors stock? I thought it was just one.

Thanks for the help Bruce! Just need to solve the relay mystery now.

[Flat6pac]

O2 sensors on the Carrera was a single in the cat.
Motor was possibly set up with the dual ox sensors to tell how each side was running.
Bruce

[BottleNose]

The ECU for the engine (which I have) has a Steve Wong custom tune that eliminated the 02 sensors.

I found out the missing relay is for the rear window defroster which I don't need out here in the desert.

Could the three wire round connector on the right be for the AC compressor which is missing on the engine?

[Flat6pac]

A/C is a single flat spade to power the compressor.
Bruce

[EdRogers]

I believe the one on the right, next to the oil filter is unused. My 84 has the same plug. There are "extra unused", wires in the harness. I always wondered what was the idea behind it, maybe an option to have the cat on that side? Or a second O2 sensor if needed?

[EdRogers]

The Bentley manual sure is useful. I was wrong,. The plug is a "test instrument connection". Still unused....

[Flat6pac]

The test connection is bolted to the intake under the gold tube on the center of the air box. It attaches to the engine case next to the case breather to measure TDC off the flywheel if it were plugged to the computer. Any more it’s superfluous.
Bruce