Sensor identification help

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Luke_P

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Hello all, I just got an 89 K3500 with the 7.4L engine and "3 speed" manual. Overall it's in good shape and I'm working through various small issues. I've gotten a lot of great info from this forum and I hope you can help me here.

I came across a sensor laying on top of the passenger side of the intake manifold and can't identify it. The sensor is beat up, only number is 6165 molded into the connector. It is connected to a single wire I'd call green.

There are no check engine lights or stored codes and the truck runs fine. It's pretty rich at idle but the temp here was 3 degrees last night so I don't expect great cold start performance.

I've attached a picture. Can anyone tell me what this might be? The business end you can't see in the picture is just a metal disc 5/8 inch diameter.

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Mike1999

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That appears to be the high pressure switch for the ac compressor. Some new replacement compressors have a plug in the spot where the switch goes and the switch never gets installed. That's my guess at least
 

Luke_P

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Thanks for the lead. Here is a picture of the a/c compressor and the single wire connection on the back. Would there normally be two sensors? I don't believe the a/c works though I haven't looked into it much. I just don't hear the compressor clutch when I push the button.
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Luke_P

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Just in case someone else runs into this, I thought I'd respond and close the case.

This turned out to be the plastic portion of the third coolant temp sensor which runs the auxiliary fan. That circuit isn't on my Haynes wiring diagram but it's sure on the truck.

The original sensor is discontinued so the shop gave me something with a spade connector that would work. The original looks like this:

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1952Chevy

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Thanks for the follow up! Always appreciated when the case gets closed.
 

GoToGuy

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Haynes manuals are crap. Try to get a Chilton service repair or get the factory service repair manuals here for free.
 

eran tomer

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Haynes manuals are crap. Try to get a Chilton service repair or get the factory service repair manuals here for free.
chiltons are crap. you can't find your arms and legs there, especially if you have the r/v/c/k book.
 

Sam Cooper

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Just in case someone else runs into this, I thought I'd respond and close the case.

This turned out to be the plastic portion of the third coolant temp sensor which runs the auxiliary fan. That circuit isn't on my Haynes wiring diagram but it's sure on the truck.

The original sensor is discontinued so the shop gave me something with a spade connector that would work. The original looks like this:

You must be registered for see images attach
Okay I just tried to make myself crazy on this one. I have a 1989 big block powered C3500. Apparently the original sensor was a GM 10096165, which was superseded by a 14080661 and also known as an ACDelco 15-4441. Standard Motor Parts made it under TS239. They were temp sensors to activate the auxiliary cooling fan in front of the radiator. All of them have now been discontinued. They only apply to the brief period of computer controlled engines in analogue vehicles (1988 - 1992?) This one had three temp sensors: 1 for the gauge, 1 for the computer and 1 for the cooling fan. Of course they are all different. The answer is to get a matched two wire sensor and pigtail that will fit the big hole in the big block cylinder head. Napa and Oreilly both have them.
 
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