Temp Gauge INOP.

[piratessoul]

I bought a '95 Wrangler with the 2.5L engine and I love it! Just one problem. The temp gauge won't register.

I have replaced the sending unit, tested the gauge, and checked every fuse. The temp gauge goes to 100 degrees when the ignition is turned on, and stays there.

Is there a relay that controls the temp gauge?

I would appreciate any help on this.

 

[SteelHeadz]

MMmmm, the temp. sensor is a one wire sensor. If the gauge registers to the max level when the sensor wire is grounded, the gauge is good and so is the wire. If the Sensor doesn't change resistance value as its heated up, its a bad sensor. Plain and simple setup. Weird situation.

 

[piratessoul]

Thanks for responding! I think I may have a lead on the cause. It may be that I changed the wrong sensor. I found a link (on another forum) that shows the temp sensor at the back of the engine and not on the Thermostat housing. That was on a 4.0L but I'm guessing my 2.5L has a similar setup.

I'll have to check it when I get home.

 

[collegeYJ]

lemme know if you figure it out because i have the exact same problem and the same year and model jeep

 

[piratessoul]

I didn't get to it last night. Had to work late. As soon as I do, I'll post what I find.

 

[piratessoul]

O.K. Here's the deal. The sending unit on the thermostat housing is not the one that controls the temp gauge. I climbed up into the engine compartment and found an electrical connector hanging loose. It's purple with a yellow stripe. Hmmm....the wire that connects to my gauge is that color!!!

I had a hard time finding the sensor that is supposed to be plugged into because it's broke off and looks like the head of a bolt.

The good news.... I have one waiting, at my local parts store, for me to pick up on my way home today.

Look on the driver's side of the valve cover, near the very back. Good luck!

 

[piratessoul]

Whoo Hoooo!!!! Finally fixed! Just as I suspected, I had changed the wrong sending unit. When I put the new one in the gauge started registering post haste!

New problem is that the heater core has a leak. I just bypassed it for now. Anyone here ever had to change one? How difficult is that?

 

[Sine Deviance]

Yep, that was the one. I actually made the same mistake as you and changed the front temp sensor first After changing the second one it all gets sorted out.

 

[boogergrnjp]

got the same problem... where is the sensor located on your 2.5?

 

[Sine Deviance]

It's in the very back of the engine, on top, on the driver's side. It's behind the throttle body and to the left if you're looking at the engine bay from the front, and it's between the valve cover and the fuel rail. It almost sits right up against the valve cover. It looks like a little nut with a plug sticking out of it. You have to go at it with an open-end wrench, sockets won't fit. It's kind of a pain because the fuel rail and some other misc stuff is right in the way.

It's relatively easy to swap out; despite the odd wrench angles I got it swapped in about five minutes. Just make sure you don't do it when the engine is hot, elsewise hot coolant will shoot out.

 

[boogergrnjp]

thanks for the info