Should have listened to Brian in the beginning.
I am going to buy a CCU hopefully in the next couple of days.
I can hear Brian snickering now. Brian, can(will) you give any tips on how to remove and replace the CCU?
Thanks again
A

Nah, I'm not one to be condescending. I've been in too many of the same situations myself. BTW, I'm not fully convinced that it's the CCU. But the data is pointing in that direction.

It comes out in 15 minutes.

Remove the ashtray.

Remove the two screws that hold the housing of the ashtray and pull it out.

Remove the radio.

On the bottom of the wood piece are two screws that secure it. Remove them.

The wood slides downward about 1/8" and then it's out. Remove the five plugs for the switches. Remove the two large plugs for the CCU and the entire wood panel with switches and CCU is now out of the vehicle.

Brian,
You make it sound so simple. Hopefully it is. Maybe this is also the time to change out my terrible stock radio. I will have to enlist the help of Sixto for that one.
Thanks again for everyones time
A

Bought a rebuilt CCU that was done by Progamma.
All buttons and dial work and look great.
Everything is great except the fact that I have no
$%^#! AC!
Did the #10 socket and ground test and its
wide open.....
Brian, could a bad compressor be the culprit?
The CCU does activate the compressor correct?
Or could it be any of the AC components are bad?
I did put in a new stereo. Could I have cut
a wire? The 2 set of wires coming of the back
of the CCU look intact.
Any, and I mean any suggestion would be greatly
appreciated. I need to know since I only have a
few days before I have to contact the seller and
inform them the CCU is a flop.
Thanks
A

I'm suffering the same fate with the '87. Three different CCU's.......none of them will operate the compressor.

In your case, you need to jump the low pressure switch on the dryer. Then check for a ground on socket #10. In fact, the manual suggests you check for continuity between socket #7 on the left plug of the CCU and socket #10 of the Klima. If you have continuity, the CCU better give you a ground signal........or it's not working properly. If you don't have continuity, then the low pressure switch is not closing because of low system pressure (but if you jumped it.......continuity had better be present).

The low pressure switch is the lower of the two dryer switches.

Brian,
How do I jump the low pressure switch on the drier and check for continuity(check continuity between #10 klima socket and ground)?
Also, want to make sure I understand you.
Place a multimeter lead on the driver side wire harness coming
of the CCU(#7) and the other lead on #10 socket of the Klima.
What does this tell me? The low pressure switch is hosed?
Thanks
A

Pull the two leads off the switch on the drier and "jump" them together so the switch is out of the circuit.

Check for continuity between the CCU (#7 socket) and the Klima (#10 socket).

If you have continuity, then put the CCU back in place and test for ground at #10 with the a/c selected. If you get a ground, the CCU is good and the system is low on Freon or the switch on the drier is bad. Don't know which without a set of gauges.

Thanks Brian, I will give it a try.
A

Brian,
Do I have to have the
key in position II?
Press defrost button?
To test continuity.
Thanks
A

__________________
1987 300SDL
187,000 miles

The CCU is unplugged...........the keyswitch and the buttons don't matter...........

Is the low pressure switch the ones with the pigtails coming off?
A

__________________
1987 300SDL
187,000 miles

Ahhhhh...LOL

__________________
1987 300SDL
187,000 miles

So ... did you jump the wires going to the low pressure switch? Did the compressor come on? I have subscribed to this thread and am anxious for news.

__________________
Doug

1987 300TD x 3
2005 E320CDI

I am at work.
I will try it later this evening.
But was wondering is the pig tail coming of the drier the temperature sensor or pressure sensor? Is there a low and high pressure sensor on the drier? Which one is the low pressure sensor?
A

__________________
1987 300SDL
187,000 miles

My AC is R134.
I think the switch is high and low?
Will this test still work Brian?
A

__________________
1987 300SDL
187,000 miles