Club 80-90 Forums

The temperature light is intermittently coming on. The light flashes and the needle goes up with just the ignition on, before the engine has even run.

Today I have cleaned the sensor on the expansion tank in the back, the sensor had a bit of sludge on it. I've cleaned the spade connectors on the thermostat housing, and the coolant is at the correct level.

I then started the van and let it idle, after about 10 min sat on the drive at idle the light started flashing and the needle came up so I put the dash fan on, then the needle went down and light stopped flashing.

I'm not sure what to try next, anybody have any ideas?

If the gauge is going to max even before starting then there is a problem with the temperature sender or the associated wiring. A problem with coolant level circuit will only move the gauge needle slightly.
Try disconnecting the wires to the sender on the thermostat housing. If the problem then goes away I would suspect the sender. If the problem is still there then there is a short to ground somewhere between the gauge and the sender.
If the engine is actually getting too hot after idling for a while then maybe the thermostat is stuck.

Thanks for the response, much appreciated.

The fault was with the dash wiring, the copper tabs on the plastic printed circuit board.