fan query

[robb]

Hi guys this morning after driving in heavy traffic the cooling fan came on after I had taken the key out of the ignition and was still on a minute later is this normal as it has never happened before thanks in advance .....Rob

[Harshan]

this is normal if you drove in heavy traffic and by the time you switched off the engine it wouldn't have reached below 92. My car did it few times before I replaced the radiator.

[steve_earwig]

I've never had the fans come on after I've stopped the engine so I though the 406 killed the power to the fans when the ignition went off I've had it on other cars though, so perhaps my 406s just never got that hot. Anyway, I don't think it's hot enough to do that in England just now so perhaps it would be best to check the cooling system for airlocks/blockages etc.

[robb]

Thanks for the replys Harsan and Steve ,will check cooling system today, just thought it strange the fan coming on after the ignition is off.Just hope it does,nt stay on long enough to drain my battery

[Harshan]

quick solution to prevent the fan to run long is to let the fan stay on (that is after taking the keys off ) for few seconds and start her up. Then fans will kick in high speed and stays for couple of seconds. You can shut the engine after fans resort to it's normal speed and they won't kick in. Trick is let the cooled down/heat exchanged water/coolant in the radiator to mix up with the system and tell the temp probe that temp aint too hot to keep the fans on even after ignition switches off.

and to answer steve, 406 does have a system to keep the fans running even after ignition switches off. To enable that logic, the temperature should be high enough to switch on the high speed mode. It won't kick in if temp goes up after you shut the engine off.