A/C Compressor won't engage
 

So I think I found the leak on my 260E....but now all of a sudden the compressor won't start. I swapped the Klimate relay with a working one and no luck.

Its filled with 32oz....so there should be no reason it should not be engaged by now...It would begin to click at like 18oz then fully engage at ~30oz

How do I check the pressure switch? Anybody done this?

EDIT: Forgot to mention I am using Enviro-safe 12a as refrigerant.

I looked up some info and it says the system only needs 60psi on the low side for the compressor to begin to kick in. Well with 110psi I should be fine.

Nobody here know how to hotwire the pressure switch temporarily to make sure the compressor hasn't blown? I looked at the wires, but couldn't make anything out of them...

I also checked fuse + replaced it for good measure to no avail.
A) Compressor dead
B) Pressure switch not functioning
C) Climate Control Unit broken.

Gotta be one of the 3....

I found the FSM PDF on it:
http://www.ps2cho.net/downloads/MB%2...ate/83-542.pdf

What does it mean "jump the two terminals"? Bridge them? I'm always weary when playing with electrics with engine running...

Use a scrap peice of wire to jump 2 termanils. Means touch them together. Sorry i know nothing about ac All I got to say is dont be afraid of electrical!! Good luck
Ps when you click ac will ur fans kick on? if so button is good

Oh the ac kick on with an electric clutch. find that wire.

The bar sensors are located on the A/C Drier, one is for the aux fan low speed to cool off the condensor (make sure the .2ohm resistor under the ABS unit is working or the fan wont turn on) the other is the saftey pressure bypass for the compressor. The wires to manually jump the ac clutch are pins 5 and 7 in the KILMA relay socket....double check that in your elec diagram though!

I just bridged the pressure switch...and the compressor did not kick in. Do I need to do the pin 5 and 7 on the Klimate relay if I already swapped the relay with the working one out of my wagon?

Thanks
Robert

Well, bridging those pins will only manually engage the A/C clutch. If your clutch is shot then that could be why bridging the pressure sensors didn't do anything. You don't want the relay in the socket rather just bridging pins 5 & 7 in the Kilma relay socket will manually activate your compressor, this should work for 86' to 89' (260E & 300E) (Sourced from the MB Service Manual).

I just checked and I have voltage at the pressure switch Ignition on, engine off. One terminal has 11.56v, the other terminal has 0.65v

Do I just need a piece of wire to bridge pin 5 & 7 to jump the relay?

Get this....I tested my 260's A/C Control Unit in my 300TE....No compressor engages on the wagon. Ok. So I put my 300TE's A/C Control Unit in the 260E, no compressor STILL!.

Wtf? That makes no sense at all. The only way that is possible is if the 260E's A/C Unit is blown, ALONG with something else in the system. :confused:

So I have eliminated Klimate Relay, jump pressure switch, A/C Control Unit. Argh!!

Seems I was wrong...No pressure in system :(

Okay...its off to someone to find where its leaking. Its not worth my time searching for it when they have all the tools necessary.