Hello all,

My 95 4.OL XLT has been having an intermittent problem with the temp gauge. lately. I get no movement as the truck warms up usually followed by the "check gauge" lamp coming on. If I am driving it sometimes starts working again but may go off too. I have replaced the sensor and tested both it and the wiring. There is some resistance between the lead and ground so it's connected somewhere.

Could it be the actual gauge in the dash? I would imagine they are not servicable?

Thanks!

 

Are you POSITIVE you have a full radiator and overflow tank?

CMOS

 

Yes, I am sure the coolant is full. I have checked is several times and there was coolant preset in the manifold when I changed the sensor last night. I drove it 34 miles to work this morning and checked it again.

I have even grounded the sensor lead to the engine, I get nothing at the gauge. I am pretty sure if you ground it the gauge should go to HOT!

 

Yup the gauge should read full scale if the temp sender lead is grounded, with the ignition switch in the "run" position (KOEO).

So check the wiring harness & any connectors, between the gauge & temp sending unit. Also carefully check the harness where it passes through the firewall, as that is a good pinch point.

Double check the crimp on the wire connector that fastens to the temp sending unit. look for corrosion, a loose crimp, broken strands, or a spot where the lead may show signs of having been pinched or cut, or vibrated about, by turbulance from the fan, or engine vibtations, such that the wire strands at the connector may e broken underneath the wires insulation.

To check this, turn the ignition key to run, but don't start the engine (KOEO) Key On Engine Off, ground the temp sending wire to the engine block or chassis, & have someone watch the temp gauge, while you gently push, pull & wiggle the wire, close to the connectors crimp & see if you can cause the temp gauge to read. If so suspect the connector crimp area.

If that doesn't prove out, with the temp connector fastened to a good ground, move to the area where the wire harness goes through the fire wall & flex that area & see if you get a positive response from the gauge.

If not, then move to the electrical connector on the rear of the instrument panel & check the sending units wire connectors crimp, by wiggeling it.

If no response, turn the key off & disconnect it & inspect it's pins & sockets for damage or corrosion.

If that checks out, then move to the gauge itself & check for connection problems to it's circuit board.

If that checks out, then suspect a internal problem with the gauge itself.

I'm of the understanding that some of these gauges can be replaced, without having to replace the entire instrument cluster.

Let us know how your trouble shoot goes.

 

pawpaw,

Thanks for the tips. I will check it out and let you know what I find. I have tested between the terminal end and ground. There is some resistance which leads me to think there is some connectivity at the gauge. I have tried the "wiggle all the wires" method with no luck. The gauge continues to work intermittently. I am going to pull the instrument cluster and test from there next.

Thanks!

 

After pulling the dash and testing the gauges out of the cluster I have determined they are indeed bad. If you try this be careful with the voltage you use to sweep the gauge needle. After testing my fuel gauge no longer works. Oh well, you need to replace them as a unit any ways. Thanks for all the help guys!

 

So I've finally got around to replacing the temp/fuel gauge in my truck and just wanted to share with you what I found. I got a dash off eBay for a good price and pulled the gauge set out. When I installed it into my cluster the temp gauge worked fine but the fuel gauge was way off!? After testing the wiring, fuel sender, etc. I realized there is another piece to the puzzle!

On the top, back of the cluster by the gauge, there is a small circuit board that slides into the cluster. It is marked "slosh gauge" so I imagine it is tied to the fuel gauge. Apparently they are somehow calibrated to each other? Once I swapped board out with the one in that came with the eBay cluster, everything worked fine. I've tested the gauge accuracy against mileage and it's pretty close. Check gauge light comes on with about 1.5 ~ 2 gals left in the tank.

I only had to run out of gas three times before I addressed the problem of no fuel/temp gauges!

 

Good find, fix, feedback & to hear you finally got your gauge problem fixed & for closing out this thread.

Yup I forgot the "slosh" circuit board, that puppy could be a culprit too, so it's a good thing for us to remember to check, when having fuel gauge reading problems.