I did attempt to check for voltage from the ACC system to the low pressure switch and ultimately the compressor clutch, but I turned things on and then got over to the connections, so it would have been a good 30 seconds before I ever got the Fluke's leads on the connectors.
It's such a small gauge wire, I'm surprised it would provide power to the clutch, as it draws a good 3-4 amps, I believe. I did not attempt to check the resistance of the clutch coil, however, since I'm not getting power to it in the first place, I don't think it's necessarily the problem. I do have the values for it, however (thanks, Wilton!) Thanks for the suggestions. I know the 126 chassis ACC well, so I'm not that far out of my comfort zone, but this system is definitely different, so hopefully someone out there has a diagram... Dan On Mar 14, 2012, at 6:05 PM, Dieselhead wrote: > Read #2 and #3 here > http://www.w124performance.com/service/W126/Index/Misc.htm > > I think you are right, that the wire from the low pressure switch to the > comp is the clutch power wire. With it off at the comp, measure resistance > of the terminal on the compressor to ground. Open or near 0 resistance means > the coil is bad. (obviously) I don't know what the resistance should be, > probably 1.5 to 3 ohms. is a good coil. > > You could also have someone turn on the AC while you are measuring the > voltage of that wire to ground. It should show 12v for a short time, until > the system detects the pulley is not turning. > > It is possible the "everything" relay replaced the Klima. Or maybe they > moved the Klima on that model. > > _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
