Mechanics

91 RANGER 2.3 COOLENT TEMP SENSOR NOT WORKING RIGHT

1991 All Other Makes All Other Models

Hey I have a 91 ranger 2.3 liter, and the coolant sensor was not working at all, so today I replaced it myself and I idled it to see if it was working right and it read up to the center mark and as usual the thermostat kicked in and it went back down, well that was the last time it read that high. Now it barely reads anything and it barely goes up even when I drove it all over town and idled it until the engine got real hot and still it just read cold.I don't quite know what to do or whats wrong with the thing, can anyone help that knows something?
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Wesman2440
May 17, 2007.



Check for bad connection at temperature sender unit and wiring clip clean it if it's needed and apply little grease before connecting it back.

Tiny
Autopop
May 18, 2007.
Dosconnect the wire at the sending unit. Use a jumper wire, connect the wire to a clean ground. Turn the ignition on without starting the engine. If the gauge reads hot the sending unit is bad. If the gauge doesn't work, the circuit may be open, may even be a fuse, or the gauge itself is bad.

Tiny
Rudpro
May 18, 2007.
Thanks I'll try that and I'll let you know how it go's

Tiny
Wesman2440
May 18, 2007.
Sorry, I was looking at an older wiring diagram, one wire going to the sensor. I believe there should be two wires going to the sensor, a light green/red and a gray/red. Turn the key on, engine off, disconnect the wires, look at gauge. It may read all the way hot or cold. Jumper the two wires in the plug together and check the gauge, it should have swung one way or the other. Ground one wire in the plug, check gauge, and do the same to the other wire. You should see movement of the gauge. When jumpering wires together and to ground do it briefly. If gauge doesn't respond it's bad. Also, do you think the thermostat is sticking. If it's stuck open, that would make the temperature gauge read low all the time.

Tiny
Rudpro
May 18, 2007.
Hey yea I have givin thought to the thermostat stickin open because the guage works but I know that its not working right and my heater is barely hot so iv given thought to the thermostat and Im gonna check it and see and im gonna replace it cuz I mean it dont cost that much and i'll just see if its that.
But thanks for your help I appreciate it alot because im brain dead right now haha.I'll keep you notified

Tiny
Wesman2440
May 18, 2007.