temperature gauge - F70


hi all, please give me some pointers with a problem on my 1988 4trak. The temperature gauge has decided to give no reading at all yesterday. I changed the water-pump over the weekend, toped up with fluid, fired up the car to check for any leaks but suddenly no reading. Can anyone help? P.S never had to touch the connection or the sensor.
thanks in advance

Couple of thoughts: 1. Are

Couple of thoughts:
1. Are you sure you didn't knock the temp sensor - can't remember off the top of my head where it is - on my vehicle there are 2x temp sensors, one for the glow plugs and the other for the gauge.
2. Check the crimp connections - one failed on mine.
3. Does the fuel gauge work? They both share the same 7v voltage reg., and mine is intermittent (it fails causing the temp and fuel gauges to go v.hot + full!).

1985 Veg oil burning Fourtrak "Rocky".

1985 Veg oil burning Fourtrak "Rocky".

temp gauge

thanks both for your suggestions, i will check and get back. My fuel gauge works fine by the way.


How did you solve your problem, on my 1994 fourtrak 2.8 turbo the sensor has definitely packed in, does anyone know where I can get a new one or will I have to change the guage and sensor with a VDO one.


Locate the sensor on the engine cylinder head, turn on the ignition and remove the wire from the sensor, short this wire to a good earth on the engine. Watch the guage, it should rise slowly to the hot position, if it does it is the sender which is at fault, if not it is the gauge, or most likely a wiring fault.

Sensors work by resistance, as they get hotter the resiatance lowers, the gauge measures this resistance, the lower the resistance, the higher the temperature reading.

One other thing to check is the water, if there is an air lock the sender will not work, it is then reliant on the cylinder head conducting heat through the switch body.


I am having the same issue with temp gauge and the fuel gauge I have checked the fuse which is fine but both gages go to max intermittently the temp gagues seems to read hotter then I think the engin is I recently fitted a new thermal sat before I found this thread thinking it was that but no difference can someone help what could be the problem