The temp gauge on my 96 Cherokee hasn't worked since I bought it so I'm finally getting around to fixing it...maybe. After doing some searches I see that 96's are supposed to have a sending unit in the back of the head. On mine, I see a plug from the wiring harness, but no sending unit (see picture). The plug is just hanging there.
It seems like I read somewhere that some 96's could have the sending unit combined with the temp sensor (in the t-stat housing). Has anyone else heard of this? I suppose that another possibility would be that it has a 97 or later head.
So I guess I'm trying to decide whether to go ahead and replace the sensor, hoping that it will fix the gauge. It seems to run fine and gas mileage is usually decent, so except for the gauge not working I wouldn't think the sensor was bad. Any thoughts?
Thanks,
Jeff

 

My 99 cherokee gauge jumps to 200 on start, even when cold. I looked for the sending unit and I don't even have the plug. I tried replacing the sensor on the thermostat but that didn't change anything. Bad Gauge? Is there another sending unit somewhere else on newer models? Any help would be apprecated!

 

I believe '96 down have 2 coolant temp sending units....rear is for the gauge and front (t-stat cover) is for the ECU. '97 up have only the front sending unit and it signals the ECU which in turn signals the gauge(s).

 

my temp gauge did not work. that sensor was broken also, $18 bucks at autozone. All fixed, guage works now!

 

What year is your XJ? Was your gauge just not working at all or was it reading incorrectly?

 

would look like this

 

ground that wire see if yuor gauge goes up

 

Did you ever figure out what was causin this...I am having low readings...around 150. Usually it was at 210.

 

I haven't fixed it yet. I was going to try grounding a wire as suggested but the connector is so small I can't get a wire in there. I though maybe I could just plug the new sensor in and ground it and see what happens. Yes, I'm an electrical dunce. I might give that a try in the next day or so (raining pretty hard here). Any reason why grounding the whole sensor wouldn't work, as opposed to just connecting a wire to the plug and grounding that?

 

Turns out my thermostat was stuck open. Replaced it and it works great.

 

Was it a "fail safe" t-stat?

 

Yup. It was the autozone branded one. I got the stant to replace it. I know people say those often times open like that, but I would eater have a fail safe since I have a 2001. Don't want to risk an overheat.

 

.......but isn't it high temp/overheat that causes it to fail open?

 

So there's no sensor or little plug screwed into the head there? I had a 96 with the rear sensor for the gauge so the port is either plugged or someone swapped heads with 97+ head.

Could always lengthen the wire and drill/tap the stat housing to accept the sensor to get ur stock temp gauge back. Not the best solution but easier than removing the head

 

I have been told they are sometimes really sensitive. It never got past 210 on the gauge. So I don't think it's a sensor.