1996 C230 Heater/AC fan finally stopped???

[frank4]

Hi,
I have a 1996 c230 estate. I had it for about a year, the heater/AC fan has been intermittantly stopping for a couple of months, now it simply doesn't work. I've checked the fuse which is fine. I removed and dismantled the control unit and checked the switch and the resistance was changing as the pot was turned so I assumed it was probably okay. (Although there is a circuit board in there with some serious looking hardware on it, but no signs of burning or cracked tracks or components),The wiring to the 3 pin plug into the big plastic "box" behind the control panel, (by the way what is that box?),buzzed out okay.
Can you help with a couple of things. Is there a relay in the circuit? and if so where is it? And where is the blower motor physically located?

Also any other ideas would be great!! Thanks

One last thing, there used to be a random loud buzzing from the overhead consol, but that has also stopped. Not sure if they could be linked??
Frank4

 

[Steve_Perry]

Hi,

Check out the following perfect 'HOW TO' that Shude put together.

http://mbclub.co.uk/forums/showthread.php?t=5482

The buzzing noise from the overhead console is from a small fan that forms part of the a/c feedback sensor circuit. I'm guessing it would be unreleated to your main a/c blower fan. It sounds like the carbon brushes on the motor that powers your main a/c fan are failing.

S.

*EDIT* P.S. Welcome to the forum

 

[frank4]

Hi Steve,
thanks for the link, it's excellent, I also picked up from the main thread that you can also use the "search" function on the forum which will be really useful.

one last question, once I have the motor out and the speed controller off can I simply stick 12V across it as a quick motor functionality check?

Many thanks
Frank4

 

[Steve_Perry]

Hi Steve,
thanks for the link, it's excellent, I also picked up from the main thread that you can also use the "search" function on the forum which will be really useful.

No problem Glad to help.

one last question, once I have the motor out and the speed controller off can I simply stick 12V across it as a quick motor functionality check?

Yes you can, I am pretty sure that Shude had the fan spinning outside it's normal location. Click the link below to see another piccy:

Piccy

Whole thread

S.

 

[frank4]

Steve,
i pulled out the blower motor and it turned out to be a loose spade connector from the speed control unit. A quick nip with a pair of pliers...bobs your uncle!!!! Now heat, air and fan control... Brill.

Many thanks Steve, the link with the pic sequence that you sent from Shude was invaluable..
P.S. The wiring is long enough to test run the exposed fan assembly on the passengers floor.

 

[Steve_Perry]

:bannana: :bannana: :bannana: Excellent!! Glad to hear you got it sorted

*EDIT* Heh I think more thanks are due for Shude for creating such a good HOW TO in the first place

S.