Repair of Part 140 830 2685 Climate Control
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Joined: Dec 2015
Posts: 7
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1999 CLK, 2000 S, 2003 SL, 2004 E
Repair of Part 140 830 2685 Climate Control
Problem: The “AUTO” push button on the Heater “Climate” Control Unit fails to initiate automatic operation.
Observations: It is more than likely that the problem is not electrical in nature… It has to do with a failed part of the push button that I call the BRIDGE. The BRIDGE operates the switch on the circuit board that initiates automatic operation. The photos attached reveal the weakness of the push button design. In my case the BRIDGE failed at one end and it was cracked at the other end. In this condition the push button failed to completely depress the switch on the circuit board.
Solution: The goal is to restore the push button to its original configuration. I pushed the BRIDGE back to its original position and loaded the backside with Silicone Sealant. I allowed the sealant to set up for 24 hrs. Then I reassembled and installed the unit. As a preventative measure, I loaded the passenger side push button with Silicone Sealant anticipating eventual failure.
It is conceivable that this fix can be performed without removing and disassembling the Climate Control Unit. Carefully pop off the cover on the push button with a thin blade such as a utility knife. See if the BRIDGE is visible and if it can be moved back to its original position. Stabilize the push button with tape so that it cannot be pushed in for at least 24 hrs. Move the BRIDGE back to its original position and load the cavity with sealant. Use a tapered nozzle and do not overfill so that the silicone oozes out of the cavity into the gap between the push button and the circuit board!
If it happens, the problem can be corrected by clearing out the silicone. If necessary, disassemble the unit and remove any access.
This repair saved $1611.82 – Price of a new unit, programming and labor. So called “rebuilt” aftermarket units are $400.00 and up with exchange. New or rebuilt unit have the same inherent weakness.
For disassembly see:
http://www.benzworld.org/forums/c208...l#post12214121
Observations: It is more than likely that the problem is not electrical in nature… It has to do with a failed part of the push button that I call the BRIDGE. The BRIDGE operates the switch on the circuit board that initiates automatic operation. The photos attached reveal the weakness of the push button design. In my case the BRIDGE failed at one end and it was cracked at the other end. In this condition the push button failed to completely depress the switch on the circuit board.
Solution: The goal is to restore the push button to its original configuration. I pushed the BRIDGE back to its original position and loaded the backside with Silicone Sealant. I allowed the sealant to set up for 24 hrs. Then I reassembled and installed the unit. As a preventative measure, I loaded the passenger side push button with Silicone Sealant anticipating eventual failure.
It is conceivable that this fix can be performed without removing and disassembling the Climate Control Unit. Carefully pop off the cover on the push button with a thin blade such as a utility knife. See if the BRIDGE is visible and if it can be moved back to its original position. Stabilize the push button with tape so that it cannot be pushed in for at least 24 hrs. Move the BRIDGE back to its original position and load the cavity with sealant. Use a tapered nozzle and do not overfill so that the silicone oozes out of the cavity into the gap between the push button and the circuit board!
If it happens, the problem can be corrected by clearing out the silicone. If necessary, disassemble the unit and remove any access.
This repair saved $1611.82 – Price of a new unit, programming and labor. So called “rebuilt” aftermarket units are $400.00 and up with exchange. New or rebuilt unit have the same inherent weakness.
For disassembly see:
http://www.benzworld.org/forums/c208...l#post12214121
Member
Joined: Nov 2001
Posts: 175
Likes: 1
From: U.S.A
CLK320, Carrera S
Great post. The bridges on my unit were completely broken so I glued (with epoxy) a narrow (0.1") piece of thin metal on the back of the button so that it would engae the switch. All is well, thanks.
