So I bought a 96 Classic that had been sitting for about a year and have been working through some of the issues that come with that one by one. Right now, I'm stuck on the cooling system. The temp gauge has been inop since I got it. The coolant was ridiculously nasty, so I flushed the system and put a new thermostat in, and all that works as it should, but still had no temp read in the dash. So I got a new temp sensor(in the thermostat housing) and replaced the harness as well. Still nothing. So before I run an aftermarket gauge or replace the cluster, is there anything else I need to check?

 

see if there a senderr on rear of cyl head driver side some years have a sensor in housing for ecu and sender for gauge .Not sure when then changed to just one switch.If you do make sure new ones for gauge and match exactly when replacing old one.

 

I don't see the sender on the back of the head.

<a href="http://imgur.com/AgnBUWW"><img src="https://i.imgur.com/AgnBUWW.jpg" title="Hosted by imgur.com" /></a>

 

Is the plug for it there did search 96 still had it ?

 

I think I may have found it. If you look at the two attached photos, you can see the wire i'm holding with my finger that comes out from what looks like goes to the sending unit on your picture. On my XJ, that wire runs to the passenger side of the motor and a piece of radiator hose is spliced into the hose that comes from the firewall and goes into the top of the thermostat housing, and it looks like that might be what was being used as the sending unit. I'm guessing the same hose on yours is one continuous piece that goes from the firewall to the housing?

If this is true, when I was going through some of the service records when I bought it, I found one where the head was replaced in 09. If different models don't have the sending unit, and a different head was what was used, then this may be a makeshift sending unit?

 

That seemed to be the issue. I pulled the sensor and hose, and there was so much rust in there that the sensor was blocked. since water doesn't flow directly through it, so was just essentially a rust trap. So I cleaned it out and reinstalled and my temp gauge is working now.

I'm not sure though, is that a good place for that sensor to be?

 

Theres should be a plug where sensor should be removeing it and installing proper sensor and fixing wiring back would be best ffix .It would appear either motor or head has been replaced .