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Mudderoy
05-16-2011, 08:50 AM
About 10 minutes into my trip in to work this morning I noticed the temp gauge needle was at the first hash mark. No way this is right. Quickly I checked to see if I left the e-fan override switch on, and I had, so I turned that off.

The temp did seem to rise slightly, but the gauge didn't read anywhere close to normal.

I've had the common issue of bad ground on the instrument cluster in the past, usually when it is cold out. So I rapped on the dash a couple of time just to see if this was the cause. Normally all of the gauges were effected though.

The needle started coming up a few times but it didn't seem to be any relation to what I was trying.

I just left it alone and thought I would just try turning the keep to the off position, then on once I got to my destination.

After a few more false rises in the gauge, it finally started working.

It is my feeling that if it was the sending unit the ECM would throw a code and the innocuous "CHECK ENGINE" light. So I suspect this is the gauge, or the connect to the gauge.

I was thinking about ordering a replacement gauge just to be ready. No way do I want to drive around in a Cherokee not knowing the temp. I don't know how you people with idiot lights do it!
msmoorenburg
05-16-2011, 09:24 AM
I'd replace the sender first
Mudderoy
05-16-2011, 09:36 AM
I'd replace the sender first

It's like new, it's only got 169k miles on it! :bang:
steph74
05-16-2011, 09:42 AM
maybe you solved your overheating problem ;)

I know you have the open system and that is highly unlikely, but could it be an air bubble stuck there ?
4.3LXJ
05-16-2011, 10:09 AM
Tony.

I forget. Do you only have one sender on the 98. The OBDI has two.
Mudderoy
05-16-2011, 11:34 AM
Tony.

I forget. Do you only have one sender on the 98. The OBDI has two.

Matt and I have had the discussion. He thinks I have two, I only think I have one. It's on the thermostat housing. So I'm not sure.
4.3LXJ
05-16-2011, 11:42 AM
The reason I asked is that the OBDI has two sensors, one for the ECM and one for the temp gauge at the rear of the head. I think you do also. You might check it. If that is the case then I would pull that wire and touch it to ground while the ignition is on. It should peg the temp gauge. If not, it is the gauge. If it does, it is the sensor.
xj4life2
05-16-2011, 12:11 PM
Only one on yours Tony OBD2
Mudderoy
05-16-2011, 12:14 PM
The reason I asked is that the OBDI has two sensors, one for the ECM and one for the temp gauge at the rear of the head. I think you do also. You might check it. If that is the case then I would pull that wire and touch it to ground while the ignition is on. It should peg the temp gauge. If not, it is the gauge. If it does, it is the sensor.

Yep, I'm remembering more of the "Matt" conversation now. If I disconnect or change the temp sensor on the thermostat housing it effects the gauge.


Only one on yours Tony OBD2

Thought so, thanks for confirming it.

Hey does anyone know if there is an easy way to attach a direct water temp gauge on the 97+?
4.3LXJ
05-16-2011, 01:45 PM
Tony, if you don't have a functional valve on your heater hose for max AC, then plumb one in line. The coolant will circulate all the time
bigjim350
05-16-2011, 02:50 PM
I'd try replacing the sensor. You get a CEL if there is no signal, not if there is a bad signal. Had the same prob on my wifes 01.
ice_cold
05-16-2011, 07:17 PM
Have you done a gauge cluster test to make sure its working right? Did this on mine and found that the fuel gauge was sticking.
To do it, hold down the odometer button, then turn the key to the run position, then release the button. The gauges will all go thru there ranges as well as the odometer will run zeros to nines. When done it will post codes for errors.

Just a thought
Mike