Some gauges don't work

Hi all,

I'm having problems with my gauges in my 95 XJ. I did search and found somethings useful but am still having problems so hoping to find new ideas on this problem. Okay I replaced the oil pressure sending unit coming off the engine. It was leaking oil and read 0 psi. Now the gauge on the instrument cluster is pegged. I let that go for a while. Now the next thing to go was the temperature gauge. It reads 0 degrees. I replaced the sending unit on the thermostat housing and it still reads 0 degrees. I don't think the thermostat is to blame because I have heat and the engine gets too hot to touch so I don't think it is stuck open. Is this thinking correct? There is only one temp sending unit for the ECU and the gauge right? So I started to think it was the instrument cluster it self. So I found a used replacement and even less gauges worked like voltage and rpms. So I put the old one back in only to have the same two gauges, engine temp and oil pressure acting the same way. I did read somewhere in the forums that someone checked a gauge by grounding it out which pegged it one the gauge which I think they were able to determine from this whether it was the gauge or the sending unit. I'm not very electrically inclined so I don't know if I want to do this and damage a new sending unit or cause other electrical problems. I also read somewhere in the forums that a bad ground on the instrument cluster will cause problems. So they ran another ground and the gauges worked correctly. Where would you ground it to? And if it was a bad ground wouldn't all the gauges not work? Thanks for any help. It would be nice to have working gauges now that I finally have it back on the road with a replaced engine.

Marcus

With the oil pressure sending unit, are you sure you got the one for the gage and not the idiot light. Possibly same issue with temp gage sending unit. I'm not sure when it changed, but I think your's is old enough to have one sending unit on the tstat housing and another at the rear of the head on the drivers side.

The temp gauge is not in the thermostat housing. Its located on the back driver side of the head, next to the valve cover.

I have a 95 and had similar electrical issues. The clips in the fuse block under the dash had gotten brittle and were broken. When checking the fuses all checked well. The power was not making it through the fuse and out into the harness. I replaced the bad clips and have had zero electrical issues since.

Thanks,

winterbeater I will have to check on the oil pressure sending unit for the gauge I didn't know there was a difference. Ah. I see the temp sending unit now Rockslut. I knew there was two when I looked in my FSM which I let someone borrow and didn't have. I asked the parts guy at the store and he insisted on more than one occasion that there was only one sending unit so I began to believe him. So what do I ask for at the parts store? Dash temp sending unit didn't get the point across. I'm also going to check the fuse box for the problems you described.

Thanks again.

Their listing should say "with light" and "with gage". Make them show you on their screen. If it's not clear, go somewhere else.

There is a coolant temperature sensor (in the thermostat housing), and a coolant temperature sender (back of the head).