240 Need some help with a wiring diagram ('80 240)

[Chuck W]

I'm looking to see if anyone has any better wiring diagrams than the Greenbook one I've got access to.

I'm working on the '80 264 GLE (now a B21FT/MS car) and I'm trying to get the oil pressure gauge hooked up. The engine is from the '85 244GLT I had. In the process of prepping the engine for the '80, I redid the harness from Alt/oil pressure sender to the 8-socket connector that's on the firewall, right at the center.

On the '85, 3 wires came to this connector from the lower pass side of the engine.

Red- Alternator warning light
Black - Oil Pressure warn light
Green - Oil pressure gauge

The first two jive with the '80 harness, but the green one does not, as none of the earlier (75-80) cars had an oil pressure gauge standard.

The wire is in the #5 or #6 socket on the connector (not in front of the car at the moment), but I lose it when it comes into the cabin as part of the harness. I've looked through the wiring diagrams, and the Greenbook and nothing is called out for that spot.

Just looking to see if anyone has any more info before I start chopping up wires.

 

[TestPoint]

Not all sockets in that 8 pin connector had wires in the harness. Are you sure that you have a wire leaving the connector?

 

[Chuck W]

Not all sockets in that 8 pin connector had wires in the harness. Are you sure that you have a wire leaving the connector?

Yup, thus why I asked. There are a couple open sockets, but this green wire is there on the chassis side. I still have the old engine (B28) in the garage, but that side of the harness is no more.

 

[nel621]

I think you answered your question. You lose the green wire coming into the cabin of your (80s ) car because there was never a gauge to begin with. The green wire may be in the harness going out to the motor but NOT in the cabin part.

 

[Chuck W]

I think you answered your question. You lose the green wire coming into the cabin of your (80s ) car because there was never a gauge to begin with. The green wire may be in the harness going out to the motor but NOT in the cabin part.

Or, it was used for something else, which is what I'm trying to discern. The wire comes into the cabin, I just can't get up to its location, so I'm trying to see where it might go (Or intend to go), to grab it from there.

 

[Chuck W]

Just got home from work and rechecked the old engine. I found the remnants of the wiring that I cut off the connector to mate it to the B21FT wiring. There is a green wire in there, for certain. It shares the same wire loom. It wasn't attached to anything on the engine any more, but it did come into (and then back out of) a female spade connector. The other end of that wire was cut off as well.

Maybe it's something specific to the V6 engine and it's K-Jet, or perhaps even the AC. Doing more digging, but hoping someone else might have an idea.

 

[Chuck W]

OK, I *think* I found what it might be. It may be from the old Lamda Sond system
Looking at the last page of THIS PDF from the Greenbooks

It shows a paired up green wire that is on the thermal switch (V6 only, apparently) that goes into the cabin to the control module. I seem to recall when I was removing all that crap, there was a wire that ran across the firewall (the thermal switch was on top of the engine). I need to dig back under the pass side of the dash to see if it's still there. It was too imbedded into the harness for me to pull out fully...

In the mean time, anyone with an early V6 with the Lamda Sond system able to verify that green wire on the thermal switch?