Another heat issue - PeachParts Mercedes-Benz Forum

psaboic · #1 12-12-2011, 11:21 AM

Quote:

Originally Posted by tangofox007

The first picture in this post shows the switch. Yours might be in a different port, however.

If your blower is running in Defrost, will it stop if you push the EC button? (Do not select OFF before selecting EC.)

Yes, if the blower is running full blast in defrost, 97% of the time if I push the EC button or the one to the left of the EC button, the fan shuts off.

tangofox007 · #2 12-12-2011, 11:54 AM

Quote:

Originally Posted by psaboic

Yes, if the blower is running full blast in defrost, 97% of the time if I push the EC button or the one to the left of the EC button, the fan shuts off.

The 3% success rate suggests a problem with a blower relay in the push button unit. There are several relays which will be in plain view when the PBU is opened. Cleaning the contacts would be a good plan. (Buttons 1-2 use a different relay than 3-4.)

http://www.peachparts.com/shopforum/attachments/diesel-discussion/48579d1192079194-diy-page-introduction-resoldering-climate-control-unit-a12_small_0012_sf.jpg

psaboic · #3 12-12-2011, 02:37 PM

Well, I tried disconnecting the low temperature switch and grounding the lead....no change, fan still dies when switching from Defrost to "EC"