Hello all!

First post, so I try not to mess up any rules here.

Until last week , when I turned off the ignition on my W220 (2003) S320 CDI, then I could hear a fan in the engine running for some minutes (I guess to cool the engine...)

Last week I removed the headlamps from the car so that I could remove a laser blocker which had sensors fixed to the front bumper.

Since then the fan does not come on when I park!

Whilst driving and idling, the temperature gauge seems reasonable (85-95 degrees), but I am concerned that this sudden change of behaviour in the fan is not correct, and that the fan should indeed be running for a few minutes when I switch ignition off? What is the expected behaviour?

Is it possible I did not reconnect something under the headlights... are there any fan connectors or sensors around that area? Or even under the front bumper... whilst pulling out the cables it is possible something got disconnected... Just, I don't want to dismantle the car again if it is not necessary. Removing the headlights seems to involve bending the front bumper slightly, so like to avoid that if possible.

Another thought... I disconnected the car battery for about 5 mins whilst I disconnected the laser blocker electrics. Perhaps that reset something, and now the fan stopping immediately when I turn off the key is actually the correct behaviour (perhaps it was wrong to overrun before?)

Finally, I tried an OBD-2 tester, but get no error codes from the "Motor" setting. Also I tried the AC diagnostic test inside the merc (holding REST and Charcoal filter buttons), and get 1 error code displayed: Diag Error: KLA V 1000

Any advice really gratefully received; I am a little worried about the sudden change of fan action with summer on the way!

Best regards, Michael.

 

I corrected the year in my first post- the car is 2003 build, not 1993!


So may I ask anyone with an S320 CDI,


When the ignition key is turned off, should the engine fan:

What does yours do?

Thanks for the help!

Michael.