406 TD Cooling fan

[Chrisj22]

Having problems with the cooling fan on my 406 1.9 TD. There is a twin fan unit on the car which I'm lead to believe is a slow and a fast unit. The fan does not currently cut in when the engine warms up. I've left it until the temp gauge reaches mid 90's. If I disconnected a cable off a brown topped switch by the fuel filter the 'slow' fan cuts in after about 15 secs. Once reconnected the fan quickly shuts off. This switch has been replaced this evening with a nice new one from Peugeot, but the problem still exists. Any one have any other ideas what to do next?

[supercharge]

mine dont even switch on at mo, which i am hoping to resolve in the tech forum here!

[mjb]

The fans should both run the same speed; either fast or slow. With the CTS unplugged, they should both run at full speed. If only one runs then one fan is broken (either jammed, failed motor or failed relay) and that will prevent slow speed operation of both (which works by the relays connecting the fans in series)