Club 80-90 Forums

We have a 1983 1.6td. The temperature gauge works fine but the warning light has never worked. So the other day on a very steep hill we didn’t know the engine was getting really hot. No damage just a bit of a fright. Any ideas how to get the warning light working? Can you buy it separately? I can’t seem to find it.

Thanks

So when you turn the key on the red flashing light does not flash to self test ?
Could well be the actual red led is faulty or a bad connection ?

If it is not the actual led , I would start at the engine bay and disconnect the plug from the low coolant sender in the header tank , this should force the signal to flash , then if no flashing leave it unplugged and go find relay 43 ( or 42 same one) in the holder above the fuse box near the earth crown and clean the connections on both the relay and it’s holder .

Cool. Thanks a lot. The light doesn’t flash when the key is in the ignition. It could well be the wiring as it is a complete mess.

However isn’t the temperature gauge fed by one wire?

The actual gauge works it is just the light that doesn’t come on. The LED is fine.

Sounds like the circuit inside the gauge or the led is faulty but check that the middle nut on the temp gauge is not loose as this provides the earth 0v connection for the temp gauge led circuit, usually if this is not tight the problem is continually flashing LED but check anyway. You are correct in that there is only one voltage source to the gauge and if that was missing the gauge needle would not function.

Inside the gauge is a small PCB that has a microchip and a few resistors and a capacitor. That circuit has two very fine wires to supply the voltage and a 0v connection to the middle nut - the wires may have broken.

The capacitor in the temp gauge fails and this prevents the LED flashing. I have replaced two on faulty gauges so it is possible to repair by replacing the capacitor but the gauge has to be removed. I dismantle the gauge by filing the brass rivets and carefully separating the case - the needle just sits in a carrier but with care the circuit can be accessed.

I have read that some have managed to replace the capacitor without dismantling the gauge.

The only alternative is to buy another.

Given my electronic skills I think I’ll buy another!

Thanks a lot, Richard