Coolant Temp Sensor Question!

[jzak]

Hey Guys,

Last time I brought my 1981 CJ5 into the mechanic, he also replaced the busted coolant temp sensor thinking it would fix some issues i've been having.

It really hasn't made much of a improvement, and when I took a closer look at it, there are two wires coming out of it. My previous CJ5 had only one wire coming out of the temp sensor. Is it possible that he installed the wrong coolant sensor?

My engine is a AMC 258 i6 / 4.2l AMC 258 i6 / 4.2l I6.

Thanks!

Josh

 

[DHugg]

jzak, my '80 CJ7 only has a single wire out. The temp sensor case is the ground to the engine block.

 

[jzak]

jzak, my '80 CJ7 only has a single wire out. The temp sensor case is the ground to the engine block.

Thanks! That's what I thought.

 

[mtnwhlr]

I've never had one with more than one wire.

 

[ThisGuyUKnow]

Post a picture please. The temp sensor should only have one stud on it. Later Fuel injection has 2 wire sensors but I can imagine him installing one,

 

[Techlight]

Just for reference sake my 84 CJ7 has a two wire threaded brass plug temp sensor that goes into the center of intake.

Out of curiosity are you getting temp readings with it ? (it sounds like it has the same plug as the single wire which is kind of interesting)

 

[Techlight]

I thought I'd add that I have both of these sensors on my 84. The two wire on the intake and the single wire on top of the head by the firewall. These posts are probably not very helpful but I did add some photos to the mix

 

[BusaDave9]

What kind of problems was your mechanic thinking the sensor would fix? The temp sensor goes only to the temp gauge. That's the only problem the sensor would fix. It doesn't go into the computer or anything else.
A bad sensor will not make the engine run poorly. (this is not true of later, fuel injected vehicles)

 

[Torxhead]

What kind of problems was your mechanic thinking the sensor would fix? The temp sensor goes only to the temp gauge. That's the only problem the sensor would fix. It doesn't go into the computer or anything else.
A bad sensor will not make the engine run poorly. (this is not true of later, fuel injected vehicles)

Dave, the later CJs that are computer equipped with a carb have a coolant temp switch that is tied into the computer. The temp sender is for the temp gauge. I am sure the names of the two get mixed up a bit.

 

[Techlight]

Thanks Torx. This is why I place asinine posts...I learn something. So the sensor on the back of the head is for the gauge and the sensor on the intake is for the computer?

 

[mtnwhlr]

Thanks Torx. This is why I place asinine posts...I learn something. So the sensor on the back of the head is for the gauge and the sensor on the intake is for the computer?

Yes