what is this plug for ?

[Jesse Menck]

It's a 2 wire plug coming down behind the rear most head and is hanging maybe 2 inches above I believe the oil pressure sensor

 

[Jesse Menck]

Hopefully that helps small black thing dead center of picture my battery died tried to get a shot from below

 

[Devin]

So it is below the right hand head (even though it's transverse, the trailing head is still on the right), and near the front or the rear of the engine, from its perspective?

 

[Jesse Menck]

Rear of engine

 

[Devin]

Sounds familiar. I have a disconnected two wire plug back there too (between the engine and the master cylinder) but I can't remember if it is grey or black

 

[Devin]

Is it this one?

 

[Banshee]

cruise control plug for the master cylinder? That's the only plug I can find in that area on my 94. Not saying that's what it is but I'm curious. The only other mystery plug I've found over there before on mine turned out to be for the under hood light but that was a long wire wrapped up and stuffed away

 

[One_Shot]

Apparently I'm blind or something cause I can't see the connector in the picture. However the only things I can think of that are back there are the vehicle speed sensor on the top of the trans where the speedo cable goes in, maybe power steering pressure switch in the pressure hose right by where it connects to the rack. I also believe that on my first gen there is a third coolant temp sensor in one of the heater hoses back there. I think all three of those are two wire sensors. Just a few ideas anyway.

 

[Jesse Menck]

Sorry if you look where the 2 braided tubes cross it's the little black thing above the lower one and to the left of the upper one it's currently hanging basically straight above the oil pressure sensor and is probably 2 inches up the block from there because the harness length it's not behind the motor toward the drivers fender but between the firewall and engine

 

[Jesse Menck]

Hmm under hood light I wonder if that's it because my under hood light is removed were they in the center

 

[Jesse Menck]

From under car

 

[Banshee]

That might be your culprit. I believe they were just off center to the drivers side a tad. Right there though

 

[One_Shot]

I don't think it's the hood light. The hood light is a bigger male connector that is grey. That one you have there is for a sensor in the heater hose. On my 91 there is a metal coolant line that goes right through there with a bung welded into it for a sensor that that connector goes to. The pipe may have been eliminated over the years if it rusted out causing a leak and they couldn't find a replacement pipe and I would guess that's what happened to yours because those braided lines are your heater hoses correct? I believe that the sensor is probably the coolant temp for the climate control but I'm not 100% on that. I can post a picture later if you need it.

 

[Banshee]

One_shot is right about the hood light. I looked and it is a bigger grey connector. Maybe I should hook that up now that I'm thinking about it.

 

[Off Road SHO]

If you can tell me the colors of the wires, I could probably tell you its function.

Tom

 

[One_Shot]

I'm curious what that sensor is actually for if you have that information. On mine the wire colors are yellow with a white tracer and the other wire is black.

 

[Off Road SHO]

Argggh! Still can't find my gen 1 EVTM so I can't be of much help. But black is always ground.

Tom

 

[Devin]

Well Tom, where'd you put it?

 

[One_Shot]

Lol hopefully you can find that manual one day Tom sounds like it has infinite SHO knowledge in it! Would be a shame for it to be gone. However this has kind of been driving me crazy what the sensor is for so I found this diagram for the HVAC online. I found the climate control does utilize what they call a CELO sensor to monitor coolant temperature to keep the heater from turning on until the engine is warm enough to provide heat on automatic climate control cars. It also happens to be a yellow/white wire and a black wire.



So anyways, long story short Jesse if your car doesn't have the sensor or doesn't have automatic climate control in the first place then I would recommend to just tie the connector somewhere out of the way and forget about it. Or if you are trying to restore the car or the climate control operation is very important to you then you can try to find the original metal heater pipe somewhere but I would imagine they are hard to come by, heck I didn't even know that it existed until you posted this. The only thing the sensor controls is the delay for when the climate control will turn the heater on if the heat setting is selected on a cold start. It will not affect the engine or anything with how the car runs or drives.