1991 polo mk2f 1043cc coupe.

Can anyone help me with a fault finding mission to fix the temp gauge please, I managed to get the cooling fan working by replacing the radiator switch, we have rewired one of the sensors in the front of the engine block, which has helped the tic over of the car. we had noticed when wiggling one of the sensor plugs the gauge needle moved slightly! havent been able to replicate it since though!

we noticed 2 single wire (yellow) senders on top rear of the head, earthed both with no effect,

Can anyone tell me what sender talks to the gauge please, or if you think its the actual gauge itself ??

many thanks in advance.

Tom

The single wire sensors that are threaded into the head are oil pressure switches. They operate the buzzer and fault light in the clocks.

The temperature sensors are clipped into the thermostat housing. There should be 2. The blue one is for engine management, the black one does the gauge. The wiring is prone to damage, so it's worth giving the wires a wiggle near the plug while someone watches the gauge. If you have the ignition on, unplug the black one and bridge the pins in the plug, the gauge should shoot right to the top. If it does, it's safe to assume your clocks are ok.

thankyou so much, that is priceless info .