Auxilary fan (electric) W202 C200

The fan starts from the moment you switch the car's ignition on. The coolant level light also stays on even if I disconnect the plug from the coolant fillertank's sensor. Is there a relay for the fan? Is there any switching from the ECU for the fan? Where is the temperature sensor located that controls the fan to bring the car's temperature down?

Thanks to anyone who will respond. SP.

Reply to
fanienaude
Loading thread data ...

Maybe it's a short in the wiring harness? What year is the car?

The low coolant light staying odd seems real weird to me, and I would thin does indicate a short?

Dunno, Marty

Reply to
Martin Joseph

It is a 1998 Model. I agree that it is a short. I traced the relay, now I have to figure out the rest of the fan circuit.

Thanks Marty!

Reply to
fanienaude

I do have new information about the fan control switch. The Bosch Scanner showed that it is the Fan Control Switch that is faulty. I got hold of an 2nd hand FCS and it works only once in the sence that I started the car and the fan stays off. I fit all the staff, removed, back and then I wanted to let the car builds up temperature so that I can confirm that the FCS operate in all it's stages. What a suprise, the same problem was back! The fan runs although the car just started, at full speed again.

To fix this I need to know more about the system, but in South Africa, information from the manufacturer is not freely availible to the public.

The connection to the FCS have four thick wires and two thin ones. The four thick ones I am ok with. One pos. and one neg. in for thhe FCS and one pos. and one neg. out to the Fan. The two thin wires is where I need to know more about. The red wire is 10V pos. and the green wire is

11V neg. at this stage.

First I cut the green neg. , switch the ign. on and the Fan blows full speed. Then I cut the red pos. , switch the ign. on and the Fan did not run. The next I did was to touch the green wire alone (the red wire still open circiut) with the Super Prope (6V) and the fan start running at low speed.

My guess is that the two thin wires communicate with the FCS by means of different amperes for the different fan stages. The big question now, how and where does the problem come from and then to fix. It is suppose to be possible, isn't it?

Come on people, lets do it. I will stay in touch.

SP

Reply to
fanienaude

Thanks for trying,

My problem has been solved by re-progamming. It was needed because of an EIS that's been changed.

SP

Reply to
fanienaude

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.