ac still not working after ac conversion 87 300SDL

[aquaman0001]

Hello,
Just had my 87 300SDL coverted to R134. Mechanic said that it could be a relay. Climate control activates and blowes air and responds to temp dial adjustment, its just doesnt blow cold air. Mechanics stated that compressor works fine but does not engage when push button on climate control is pressed. Tach works fine(does that rule out the Klima relay?)
New drier and temp switch. Any suggestions would be greatly appreciated.
A

[Dervman]

Start with the basics. First check the #5 Fuse in the fusebox. This powers the A/C compressor and Aux. Water Pump and the ACC. If it is blown, there is probably a reason. Bad A/C Clutch & Seized Aux. Water Pump are the most likely. If the fuse is OK then next up is the Klima relay. I had an intermittant problem with my A/C cutting in and out (mostly out!) and after removing and reinstalling the Klima relay it has (so far) been working fine. I think the pins were dirty and not making good contact. It could also be a bad Klima Relay or possibly the speed sensor on the back of the compressor.
Good Luck.

[aquaman0001]

Dervman,
Thanks for the response. Where is the Klima relay located and is there a way to troubleshoot to see if it is the relay?
Thanks
A

[aquaman0001]

Anyone know where to get a used working klima relay?

[Brian Carlton]

Originally Posted by aquaman0001

Anyone know where to get a used working klima relay?

Don't jump to any conclusions.

Time to perform some checks to determine if the problem is the CCU or the Klima relay.......or one of the signals to the Klima relay. A brand new relay won't give you any a/c if one of the signals to the relay is not in spec.

So, are you willing to do some checks with a volt/ohmmeter?

They'll take a bit of time to sort out.......but.......you'll know what the problem is when we get done.

[aquaman0001]

Brian,
If you can give me some detailed instructions I can follow them.
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[Brian Carlton]

Originally Posted by aquaman0001

Brian,
If you can give me some detailed instructions I can follow them.
A

Step 1:

Locate Klima relay and pull it out of it's sockets (a bit difficult.....you really need to pull).

Connect an ohmmeter between socket #10 and the battery ground.

Turn key to position II.

Press defrost button on the CCU..

See if there is continuity to ground.

If there is, then the CCU is functioning properly for this test. If not, then the CCU is not signaling the Klima and either it or the low pressure switch is the culprit.

Report back with results.

[aquaman0001]

Is the relay under the hood or behind the CCU?
A

[Brian Carlton]

Originally Posted by aquaman0001

Is the relay under the hood or behind the CCU?
A

Under hood.......directly in front of driver........small black box........about the size of a large pack of cigarettes...........might say "KLIMA" somewhere on the outside.........pulls straight up to disengage from sockets.........

[Hit Man X]

I'm trying to score a CCU from a member here for my L, I'm close to mine working. Ordered the rest of the parts last Friday.

[aquaman0001]

Resistance was hovering around 4.5.
So is it new Klima time?????
Where can I get one that wont break by
budget?
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[Brian Carlton]

Originally Posted by aquaman0001

Resistance was hovering around 4.5.
So is it new Klima time?????
Where can I get one that wont break by
budget?
A

What, exactly did you do?

The resistance cannot be 4.5. Either it's open (infinite) or its 0 (continuity).

My guess is that it's 0 and the meter is not calibrated.

Run the test again and press the economy button and see if you get an infinite reading.........then press the middle button and see if the reading drops to 0.

[aquaman0001]

The resistance was slowly going down. It could have gone lower but I was looking for a reading of infinity, which it was not. I wil try it agian tomorrow.
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[Brian Carlton]

Originally Posted by aquaman0001

The resistance was slowly going down. It could have gone lower but I was looking for a reading of infinity, which it was not. I wil try it agian tomorrow.
A

You are looking for continuity to ground with the ignition on and the middle button pressed. Without a ground signal to socket #10, the Klima won't start the compressor.

[aquaman0001]

That reading was in mega ohms so it is open.
Can you test the CCU? Test the low pressure swith and it had continuity.
A