I had that with my 300D, I was glad to learn I only had to replace the electrical portion of the switch, not the whole switch (much cheaper).

yep, last time I looked I think the part was around $30. I'll get around to it one of these days...

__________________
-livin' in the terminally flippant zone

The evaporator is cleaned and back in its box.....
waiting on new pink vacuum "bulbs" or whatever you call them.
All the ac lines have been flushed along with condenser,new expansion valve & dryer with new pressure /temp switches ready to go in.
Compressor is off the car and i drained/blew out all the oil best i could
I am thinking about putting this compressor back on the car....Its a rebuilt Denso and I have no idea how long ago it was replaced...any comment on this?
Plan on putting in 134a ....Any where i can find out how much this car should take ? (86 300sdl)

will add pag 100 oil ....any idea where i can find out how much to use?

should it be installed in the compressor and in the dryer?

Should the psi readings on the low/high read about 30/250?

Is there any known line filter for the ac system that can be installed to prevent any crap i may have missed from going through parts it shouldnt???

Bump.
Is that your final ansa?

Well i got everything put back together today and the air is blowing cold
but to get the compressor to run i had to jump pins 5 & 7 ... didnt have to do this before...
Is there a test or group of test i can do to find out if the klima is bad or the ccu or some other electrical gremlin??
the push buttons all work fine on the climate control and the blower motor comes on fine but the compressor wont unless the pins are jumped.
HELP!

First test is to determine if you are getting a ground signal from the CCU to socket #10 of the Klima. Pull the Klima, start the engine, and select the middle button and turn the temperature down. You need to have continuity to ground on socket #10. If so, then we proceed to the Klima itself..........or one of it's many input signals.........

the klima was out already (jumper wires to run compressor)...
I removed the jumper .
started the car
pushed middle button on climate control
turned down cold control a bit
put fan on automatic
tested socket 10 for cont.. to ground

Test failed.....no continuity

Keep in mind the whole dash is still out of this car...
wires dangling everywhere!!! but it sure makes them easy to get to.

found a couple more tests that i ran....

test 1
connect multimeter to sockets 9&11 with 5&7 jumpered to run comp.
run engine at idle
min value should be .3 volts
.3 was what it tested at....that is supposed to tes rpm sensor i guess

test 2
connect pole 1&2
run engine at idle
value greater than 2.8 volts
mine tested at about 4.2 volts

that is supposed to tes rpm signal from eds control unit (whatever the heck that is)

If these test ok which they did....
it says replace AC compessor control unit a.k.a the klima relay.

This thing appeared to work before i re worked the whole ac system....what gives...is this how they go bad??

Go over to the dryer. There are two electrical switches on the dryer. The lower switch........off center..........is the low pressure cutout switch. Jump this switch.

Run the same test again and check for ground at socket #10 of the Klima relay with the CCU set for a/c.

Both the pressure and temp switches are brand new along with the dryer...
am i doing this to check the wiring or the switch?

OK OK call me a dummy
I redid the original test
socket 10 to ground....there IS continuity
What a dim bulb... I was trying to make continuity through the pos post on the battery.
Just to make sure i got continuity to ground through some bolts mounted to the body of the car.

If you've performed all your tests correctly and the data is valid, the Klima itself needs to be replaced.

Thank you for your help...It is much appreciated.

Is this relay a common problem...was there something i could have done that made it go bad?
It was working before i tore the ac system apart.

Where is a good place to get one at a reasonable price?

The Klima is frequently declared the culprit when the a/c compressor won't start. However, due to all of the associated inputs, it is frequently found that one of the inputs is out of spec and the Klima is simply doing it's job.

Furthermore, a Klima does not typically go bad simply because you have previously worked on the a/c system. Therefore, your data is suspect. You may find that a new Klima performs in exactly the same fashion as your existing unit. But, I don't see any other possibility with the data that you've presented.

They are available from all the online sources.........but they're not cheap. If you can find a known good used unit for testing, that's the way to do.

Well since i dont have the luxury of having a klima laying around i went and checked the data.

heres what i found...
The test with the #10 socket.... i switched the leads black one in socket 10 red one to ground....beeeep continuity, however the other way around there is no beeeep.(this is obviously what i did the first time when i got a failed test then tried the same thing again with the leads switched and the test seemed ok)
I thought continuity is continuity....
I did the same test jumping the pressure switch....same result... one way it beeeps the other it doesnt.

I did this on the klima relay also from pin number 1 to 7 there is continuity one way but if you switch leads there is not.

Where do you go from here??