156 JTS overheat

[Dr Chuff]

The overheat is caused by the radiator fan not coming on.
I've checked the usual suspects.
Fan works, fan resistor okay, relays working, temp sensor appears to work (gauge is showing sensible values), cooling system works whilst on the move.
Fan does not start with AC.

Any ideas before I succumb to a garage?

Thanks,
DrC

[V6Alfisti]

Not sure if it's the same with a 156, but most cars have one temp switch/sensor directly in the rad and another one in the engine.

You are probably getting the good reading from the Engine and the rad sensor has failed?

Also is the engine thermostat working? (check coolant output pipe from engine)

[Mr Flaky]

Are both fans not working? (the main one you can hear inside the car, the smaller one you will have to open the bonnet to hear going, comes on prior to the main one), the main one should come on at just over 90, I would get it down to a garage and get the fans tested and your thermostat, also double check the fins on your radiator can corrode very badly.

Hopefully its something simple, and not the water pump, by the way do you know if this has been replaced with one that has metal impellors or is it the original plastic one?

[Dr Chuff]

Turns out it was a broken wire between the ECU and fan relay.
Very difficult to diagnose.
The newer 156s (JTS) have only one fan, with 2 speeds.

Fixed by DTR Sports at a very reasonable price, although it took best part of 4 days.

Dr C