406 Rad cooling fans dead.

Firstly is 12V reaching the fans? If so is the ground connection ok. Can you measure resistance across the motor. I don't know what the wattage of the motors are but you should see a lowish resistance but not a dead short obviously. Do the fans run if you put 12 V on them from a separate feed?

Not sure about the earlier models, but the facelift models ('99 on) have a box in front of the radiator containing several relays which control the fan; the box catches a lot of water and it can get inside the box and corrode the relays. You need to take off the front grill to access it. Martin

Have you checked the thermostatic switch? I don't know specifically about the 406, but it's usually screwed into the side of the radiator.

Withdraw the connector from the switch and bridge the contacts. Do the fans now work?

Peter

That's worth knowing thanks

Thanks to everyone for your suggestions. I've tried everything I can, but failed. There is no 12 volts reaching the fans. With a battery connected directly to them they run ok.

I can't find a thermostatic switch despite looking, although as you say there must be one somewhere. A mechanic who has seen a similar problem told me he had to have the ECU replaced - not an option I'd consider on a car this old. Think I'll hard wire the fans to a BIG switch on the dash!

Cheers Chris

suggestions?

series

Mike, this is exactly what I am experiencing with my 1998 406 2.0. Cn you provide me with the information I will require to fault it please. Q-Ball

You have had a better response from the group than I did. If you look at my recent post: 406SV - expensive 120k service you will see I was puzzled why they replaced both fan motors (and, according to the invoice, did not replace and sensors or relays). Both motors seem to work OK. The vehicle had done 120k and I was not overly concerned provided they fixed the problem. And they did. There has been no sign of overheating since. It may be that these motors, when aged, bind up during operation - that is the only possibility I can think of for the fix having worked (unless they replaced sensors/relays and forgot to charge - not likely!)