c32 amg cooling fan remains on , help

[Billy albert]

Hi noticed today my cooling fan stays on all the time untill i turn engine off.
coolant ok, temp gauge ok, bet your gonna say it needs plugging in.

I am guessing temp sender is shot, and ecu is panicking. what do you think people. if i continue to drive the car i recon fan will burn out .

thanks in advance

Bill

 

[elite_504]

Not just because the air con is running is it?
Try knocking the a/c off and driving for a bit, and seeing if it makes a difference. Has been rather warm the last couple of days both inside and out, but I must say I haven't noticed anything abnormal with the fan. ...

 

[Billy albert]

defo not that mate does all time even when ac is off and cold start

 

[Benza750]

We had a w203 do this and it was a faulty pressure sensor for the A/c system, located bottom of condenser where the pipes fix on to it.
Try unplugging to see if it stops.
Cooling fan was running constantly, was ok after we replaced sensor.

 

[Billy albert]

We had a w203 do this and it was a faulty pressure sensor for the A/c system, located bottom of condenser where the pipes fix on to it.
Try unplugging to see if it stops.
Cooling fan was running constantly, was ok after we replaced sensor.

how did you come across it , did you read a fault code ?

 

[BlackC55]

Check the fan control unit (on the fan itself) for water ingress. Common as muck to fail.

 

[Benza750]

I carnt remember getting a fault code for it, we came across it by chance as in 10 years on Mercedes it is the only one we have seen do it but definatly one to remember.

 

[Billy albert]

Check the fan control unit (on the fan itself) for water ingress. Common as muck to fail.

Hi pal , can you be more specific where exactly is it on the fan and do I need to replace fan and do you recon it's fried my ecu as I have read some scaremongers on another mb site

 

[Billy albert]

Just tried a code reader on it not star , no codes

 

[brucemillar]

Billy

The control unit is part of the fan shroud assembly in the bottom corner (cant remember which side, sorry) It failed on mine so I bought a whole assy from Dronsfields. Took about 15 minutes to replace from above. Not wort replacing just the board as you need to get at it from below. So under-tray off job.

 

[Billy albert]

Did you have same prob mate

 

[Billy albert]

Also Checked plug connector seems dry

 

[Billy albert]

now coolant visit workshop, on dash.

checked wires for obvious probs, pulled fuse on ac , no avail still persists , hellllp

 

[BlackC55]

You need a Star.

I expect it will be the fan. But you need to do tests with a Star.

 

[Billy albert]

You need a Star.

I expect it will be the fan. But you need to do tests with a Star.

thought i would have to bite the bullet here with star, just hope my car will make it to my preferred independent.

its about an hour away , shall i disconnect the fan, or leave it on.

 

[BlackC55]

Leave it on.

 

[Billy albert]

Ecu broken need help here

 

[Billy albert]

Thanks Oli , sent ECU to AC tronics, fingers crossed

Alex Crow did tell me about AC tronics but my head wasnt in it on the phone doh

 

[Billy albert]

No luck with ac tronics they can't do anymore checks

The fault code is p1999 open circuit fan

Coolant visit workshop on dash

Fan stays running

What the hell am I to do ?

 

[trapperjohn]

Probably get blown out of the water for this. Could a Kenlow type fan be fitted in its place.