Coolfam01

First, yes I searched the posts' and all the other forums posts looking for days now how to fix the problem. First the inner fan wasn't spining due to it catching on a plastic part and the dual fans had stoped also. Fixed the inner fan got it to spin as well as got the other two on by holding the auto buttons. It was fine for a few days then car started having overheating problems and now the two dual fan unit is not working. Would I need to replace them or could there be another problem and yes i checked over every fuse in the car just in case but still no luck I cannot run the ac without the car overheating (record heat here in az for the last days of summer....). Any ideas what it could be?

Pancho

Blower regulator. Some German pointy headed engineers decided it would be clever to link in-line the auxiliary engine fans to the cabin blower, so that if the blower regulator fails, then your fans don't spin, and your all alloy engine overheats. And to think that these folks at one time made the best war machines on the planet. Oh, Germany, what has become of you. The engine is sacrificed because of the cabin blower. Brilliant.

Made an instructional.

Here's a link:
http://www.panchogun.com/FVWebPhotos...bin-Filter.jpg

Coolfam01

Thanks for your help. I had seen this link already but thought that since they had already been running that they should work. I did find out that my son had read another post that talked about lowering the tempature (or something like that) and now he doesn't know what he did or how to un-do it. I will have him check the blower regulator.

Pancho

You're welcome. Regarding replacing the auxiliary fans, it's very, very, unlikely that both fans would fail at the same time--each fan has its own motor. Both fans are not working because they are not receiving a common current. This current is influenced by the blower regulator. When the a/c is running, the blower regulator, which controls the cabin fan and the auxiliary fans, signals the auxiliary fans to kick on. These fans blow into the a/c condenser, and the radiator. You can see that the condenser is bolted to the radiator. The auxiliary fans help cool the engine when it heats up--on a hot day; in stalled traffic; stopped at a light; when the a/c is running. The auxiliary fans sometimes will continue to run when the engine is shut down, to help it cool down. When the blower regulator fails, these fans stop running, and/or your cabin fan will stop running, and your a/c will not blow into the car, and/or your engine will heat up. It's about a 30 minute job to replace the regulator and the cabin filter, and it's not a dirty job. Don't buy the regulator from the dealer, unless you want to pay $300 for an $60 part. You do have to sort of squeeze into the passenger foot well, upside down. I have replaced two blower regulators on my car, each one lasting about 5 years. It's a Mercedes thing. There are too many of these Mercedes things.

As to the "lowering the temperature", I don't know what that would be, unless he adjusted the thermostat setting on the dash control unit to where the a/c would not activate, and that might keep the auxiliary fans from coming on.

Coolfam01

Yep! He did adjust the thermostat. I can run the air conditioner but when I change the setting to circulate throughout the car, the car overheats. I have tried to reset it again. You can hear it clicking but the fans don't come on. When I start the car, the fans don't come on. So, right now just running it like that.