PeachParts Mercedes-Benz Forum - View Single Post

Chadahar · #3 12-20-2007, 07:12 PM

Thanks John,

I opened up the original CCU that came with the car(PO's had not replaced it) and it had the two mother boards and two wing boards. The PO had not disconnected the mono valve(bad) or the AWP (bad) so they fried the original unit before I got the car, along with the help of a dead heater blower motor.
The CCU in there now is, as I said, one mother board and two wing boards. It probably died too. As my heater(monovalve(either plugged in or disconnected),gives heat through the defroster vents and the lower dash vents.
The original Heat sensor (cabin) smoked and I replaced it with a used one. I need to remove it and test it too.

All this points to an incorrect CCU, or maybe some of the electrical components blew as the only heat I have is defrost and only if I'm moving. None of the traces are burned through, but the one less relay and the one less mother board concerns me.

I'm a bit P.O.'d in that a couple used parts I just bought were useless. I will inform the parties concerned. I don't mind buying used parts if they are as represented. Good means good and working, not just all there. As in a used AWP that had the armature rusted to the field magnet. No way in heck that was EVER tested.

So back to the drawing board. Get a good Soldering iron and try to fix my original CCU. luckily it has just two burnt traces, easily fixed. Wish I had found the correct AWP plug and disconnected it when I first read these will fry the CCU. I unplugged the mono valve instead.

I'll check both of the parts you recommended.

I am more than a little disheartened.