Coolant temp gauge problem – Please Help

[WhiteCobra95]

The coolant temp gauge in my stock cluster stopped working last year. This year, it turns on and off intermittently. I assumed it was just the sender, but I didn’t have time to pursue it until now. I just replaced the sender (the one wire display sensor on the driver’s side of the motor) and it did not change anything. The gauge still doesn’t display even when the car’s warmed up. I measured the resistance of the sender fully warm and it’s about 45 ohms, as compared with 330 ohms cold. I also measured the pull-up voltage (ignition on, sensor unplugged) and got 1.5 V. I tried grounding out the wire which should indicate extremely hot, but the gauge still reads cold.

Has anyone else had this problem or something similar? Is there voltage regulator like older cars? Can the coolant gauge be serviced or will I have to replace the whole thing?

Thank you, Mike

 

[cjones]

test the wire at the instrument cluster pin #3 R/W

test for power to gauge

power comes straight from fuse # 15 to cluster no more voltage regulator for cluster. pin #10 R/Y

 

[Zero_chance]

I have the same exact problem with the car I bought a month or so ago. The temp gauge never works, sometimes after a hot soak itll creep up almost to the the start of the readings but then itll fall back down to nothing. I just threw a new sending unit at it on thursday when I did the coolant flush hoping it was something simple (never is, right?). Unfortunately since were a Lincoln dealership we dont have any older Mustang EVTMs and the online one for 95 doesnt work. Back to the draweing board on Monday I guess.

 

[urban96]

time for an autometer gauge. and if u dont care about the stock one "working" i would just put it right in the stock location on the lower intake where the stock sender is

 

[Zero_chance]

Yeah Im already pricing out some Autometer phantom gauges. Figure to get oil pressure and water temperature. Being a mechanic though I still wanna figure out exactly what the problem is.

 

[GTA_V6_Mustang]

One thing I have noticed with these cars. The little motor that turns the needles for our gauges on our dash likes to crap itself. So most ppl go out and replace the whole gauge cluster. I personally ifnd it cheaper to go to a junk yard and just pull one out of any old mustang there. Could even be a 6cyl. all the same. But first check the power to the gauge and if you have power check the ground side. If thats good then take the guage out and take the little motor out the turns the needle. Check if its stuck to the face and check to see that there is no visual damage. You might also be able to check continuity across the little motor. If all else feels just debo one from a junk yard. Comes right out all you need is a torx screw driver and a pocket screw driver. It will pop right out.