Cooling fan problem

[chaz1702]

Hi all w209 2003 clk cooling fan occasionally kicks in but not for long does anybody know what voltage should come down the signal wire into the fan module? And the location of the sensor that tells the fans to come on and how to test them?


Thanks in advance

 

[BlackC55]

It's supposed to kick in occasionally, it's controlled by the engine control unit and the AC control unit.

 

[chaz1702]

Just an update to help anybody else who had our problem, we purchased a used fan on ebay after diagnosing our module had failed, the used one stuck on full boar all the time due to another faulty module, therefore i call many motor factors that i usually use they all said if i wanted a fan with the module it was dealer only, mercedes said somewhere in the region of £410 plus vat so i did some digging online and found that mercedes a2035000293kz crossed over to nrf 47293 and various other makes i purchased a nrf 47293 from bestpartstore.co.uk which is german based and we fitted it last night and it works fine although the wattage of the motor is lower than the original, just a side note about bestpartstore.co.uk they say ready to be dispatched in 24hrs it took them about 4 days incl weekend to dispatch but i got it and couldnt reccomend them highly enough

Hope it helps at least 1 person cheers charlie