Montego high engine temperature warning lamp and temperature gauge, are crazy!

[Pedro G]

My high engine temperature warning lamp and Engine temperature gauge, both connected to the ECU via pin 13, are crazy,

When I starting the engine, begins to rise quickly and to show the lamp intermittently and at the moment, it goes down to zero and the lamp is turned off, to do it again, so indefinitely.

I have replaced the ECU with an identical one and the same thing happens. The car works normally.

Has anyone had this same problem?

I would appreciate a lot of information on this!

Best regards.

[Pedro G]

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[robert1]

I have seen this on a peugeot 206, it was a bad ground. It had 0.6v between the engine and body.

[Doctordiesel77]

If the engine still runs ok then could be the circuit board in the instrument panel.

[Jeff Turbo]

Sometimes when this happens it's a faulty temperature sendor or faulty fuel ecu.

[Doctordiesel77]

Sometimes when this happens it's a faulty temperature sendor or faulty fuel ecu.

I wondered if it could be the sender, but would it not make it run badly?

[Jeff Turbo]

I wondered if it could be the sender, but would it not make it run badly?

Would make it possibly run rich. If a carb with a manual choke it wouldn't be as bad. Warning light comes on when the temperature on the guage gets too high automatically. If the car isn't overheating I would change the temp sensor first, then the fuel ecu if that doesn't work

[Pedro G]

I have changed the fuel ECU for another and it continues with the same problem, I will change the sensor but when disconnecting the cables from the sensor it should go to zero or maximum and continues to go up and down.

Thank you very much for your´s answers

[Doctordiesel77]

I have changed the fuel ECU for another and it continues with the same problem, I will change the sensor but when disconnecting the cables from the sensor it should go to zero or maximum and continues to go up and down.

Thank you very much for your´s answers

It might be worth disconnecting the wire from the ecu to the gauge to see what happens?

[Jeff Turbo]

Have a read, it might help https://maestro.org.uk/forums/forum/...-temp-warnings