1999-C240 Heater Fan Problem

[captainsimon]

Hi

I hope someone here can help, I have a 1999 C240 Elegance and the interior fan has stopped working on all setting.
I have tried the fuse and that is OK.

Is this a common problem with an easy fix?

Can anyone point me in the right direction.

Thanks in Advance.

 

[television]

The heater box is in the link, the fault is normally the reg pack 395 or the fan 390

http://www.detali.ru/cat/oem_mb2.as...GM=716.626&CT=F&cat=45H&SID=83&SGR=045&SGN=01

 

[jberks]

The fan is controlled by a regulator. Not sure where the reg is on the C but on the E it was in the bottom of the fan housing behind the passenger footwell. Pull the under tray out and have a look up. Mine was connected via a 3 pin rectangular plug through the housing.

Once found, it should have a constant live from the fuse and a variable live from the switch (plus the earth). The regulator should then have a variable output going directly to the fan. Check in and out current and you should be well on your way to solving it.

 

[captainsimon]

The heater box is in the link, the fault is normally the reg pack 395 or the fan 390

http://www.detali.ru/cat/oem_mb2.as...GM=716.626&CT=F&cat=45H&SID=83&SGR=045&SGN=01

Thank You for the reply.

Can you tell me where I would find these parts (is it under the dash passenger side?)

 

[jberks]

under dash, passenger side behind the glove box. Going by that diagram, it's exactly as I described so drop the passenger under dash tray and pull the rectangular plug from the regulator and test the voltages. One pin -ve, one +12v and the other 0-say 7v based on switch position.
If the +12v is ok then the fuse is fine. If the 0-7v stays at 0 you have a switch fault, -ve speaks for itself. If all ok, then drop the regulator and check the output for a given setting. If ok, then your' fan is duff. It's normally the regulator though.
All very easy DIY stuff - I replaced mine in 20mins.

 

[captainsimon]

Thanks for all your help and info, it turned out to be the fan itself that had failed.

The motor brushes were knacked and the com was very dirty. Merc price for the motor was £250 but I got it from Eurocar Parts and it came to £120 and this unit was made by Valeo (the exact same brand that came out of the car from mercs.

 

[anyweb]

that's unreal, when my heater motor failed on my 190d, i bought the mercedes replacement from the mb dealer locally for 60 quid, which i thought was reasonable.

cheers
anyweb

 

[jberks]

Good result.
I'll not mention the fact that some folk have replaced the brushes for a few pennies!

Odd though - I wouldn't have expected the brushes to fail for a good few years yet.

 

[captainsimon]

Its a company car that owes us no money, i'm an engineer and have had trouble in the past finding brushes so did not go down that route.

The fan on the car is so quite on the low settings that I would imagine that the fan has done thousands of hours of work when it has not been needed (just left on with the driver not knowing).

The com was also black and worn even after using com cleaner fibre sticks the shaft also seemed very loose (bearing).

I decided that it would be uneconimical to repair the unit so replaced instead.

I'm concerned about Merc prices as the unit I got from Europarts was exactly the same part Siemens motor branded under the Valeo badge it was not and not a pattern copy

 

[television]

Its a company car that owes us no money, i'm an engineer and have had trouble in the past finding brushes so did not go down that route.

The fan on the car is so quite on the low settings that I would imagine that the fan has done thousands of hours of work when it has not been needed (just left on with the driver not knowing).

The com was also black and worn even after using com cleaner fibre sticks the shaft also seemed very loose (bearing).

I decided that it would be uneconimical to repair the unit so replaced instead.

I'm concerned about Merc prices as the unit I got from Europarts was exactly the same part Siemens motor branded under the Valeo badge it was not and not a pattern copy

I understand your concern over some part prices, we all are and some are just plain stupid. It seems very wrong to me that they are so high, the reg pack that is only a simple darlington pair retails at some £150 and a new member has put a link where they can be bought for £45

 

[jberks]

off track but car parts prices rarely bear any relation to their true value. The best I ever had was when updating my Ford Escort many years ago. I wanted to add headrests but was having trouble matching the correct part and trim code. They finally tracked down the right part but on arrival it was the dark blue, so we returned them and re-ordered exactly the same but in light blue. When they arrived they were £20 more!

 

[anyweb]

ah light blue, that's more expensive though !