PeachParts Mercedes-Benz Forum - View Single Post - Something wrong with w126 climate control system?

tinypanzer · #6 05-15-2009, 07:19 PM

You probably just blew the blower fuse, which is located near the main fuse box, but in a separate little black box off to the side that contains a single 40 amp fuse strip. Those usually go bad anyway. Couldn't find one at the MB dealer, but a VW dealer had it.....

So you replaced the CCU huh? Did you get a new one or one from a junkyard? If it's new then we can rule out other CCU issues....

As to other fuses, they can appear good and still be bad if they are the originals. The old style German fuses get oxidized on the ends and stop working. Try spinning them around a few times in their sockets to chew off that oxidization.

If still no luck, hook a volt meter to the AC compressor clutch wires. See if there is voltage present when you turn the AC on. If not, it's probably the relay, or possibly the high pressure cut off switch, assuming the CCU you put in is good. Also, try this with the temp wheel ALL the way to cold until it CLICKS..... This will rule out a bad interior temp sensor.

If there is voltage, but the compressor still won't kick in, then the clutch is bad.