KLIMA Basics missing from this forum

[Keebler64]

Okay, put a 12v battery directly to the compressor/clutch, and it actuates just fine. So I put the shorted klima (KL & 87 pins) on, and nothing still. No Tach, no Compressor engagement. And with or without the Klima, and regardless of A/C state (on/off), fuse 11 gets super hot.

Any other suggestions? I'm away from my multimeter at the moment. (its at home), so I can't test the volt/amperage at the moment. Aux. Water Pump maybe? The Klima is toast regardless. Don't think it could work with only one functional relay inside.

[Keebler64]

FOUND IT!

It was the OVP Relay. So add that to the list of commonly listed options that can be the culprit. Took a bit of searching on here, but what tipped me off after rechecking, was a post that mentioned the ABS light and no Tach, in relation to the OVP.

So, low-and-behold, checked the OVP as well, it was blown. Klima is actually working with only 1 fully operational relay. (The second relay was missing one of two contacts and won't disconnect all the time, its also discolored and burnt compared to the operational relay.)

All that aside, it looks like a pretty simple circuitboard. If someone could replicate the board, I can solder everything together. (I don't have a print station.) Anyway, thanks all. This is a great board.

[Vegestar]

This thread was incredibly helpful! I just repaired two 85 300D's A/C systems, both customers have been bugging me for years. Now I am going to attempt to repair the KLIMA relay as I used the two I had in my parts reserves. I also have a much better understanding of the 603 systems now as well and I can tackle the A/C on my 87 300D now. Thanks for the help!

[ngarover]

Been having A/C gremlins in my 85 300CD the clutch would engage then quit then engage... sometimes not... When it would engage, the system would work and blow cold, other times.. well I was getting hot as hell.

Opened up this recently discovered Kilma (which means "kill ma" AC if I'm broken) and sure enough, one of the brass leads was burned right in half... some wire and solder and she's all better. Turned on the system, it ran for 30 seconds, and bang! the belt broke. (new belt only 2 weeks old). So I put a new one on this morning and noticed that the pulleys where not aligning right. Not sure how I missed that the first time putting on the belt, but I had done all 4 and it was getting late...

A little more research and it looks like some PO put the washers in the wrong place in the bottom bolt. moved it and every things straight as an arrow now and working.

Now I just need to clean the condenser so air will blow stronger and I should be all set.

[shertex]

Reading an old thread, trying to learn about my klima. Why does the kickdown switch cause the klima to open and thus the compressor clutch to disengage? What's the relationship betwen kickdown and the compressor?

Is it that the AC would sap power from the acceleration that you want at that moment?

Originally Posted by Brian Carlton

The "Klima" on the '85 is a solid state relay that controls the compressor clutch.

It takes signals from the following:

1) Signal from the CCU going through the Evap. temp switch and the low pressure cutout switch. This signal tells the Klima to close.

2) Signal from the kickdown switch. This signal tells the Klima to open.

3) Signal from a temperature switch. This signal tells the Klima to open if the temperature it above the setpoint.

4) Signal from the tach. I can't figure what the Klima does with this on the '85.


So, if the signal is present from the CCU and there is no kickdown signal and no overtemp signal, the Klima should close the relay and the clutch should engage.

[Brian Carlton]

Originally Posted by shertex

Reading an old thread, trying to learn about my klima. Why does the kickdown switch cause the klima to open and thus the compressor clutch to disengage? What's the relationship betwen kickdown and the compressor?

Is it that the AC with sap power from the acceleration that you want at that moment?

Yep.

[atomicmass2]

Hey all. I'm having A/C issues and this thread has been a fantastic source. So here's where I'm at...I have an intermittent issue with my A/C. It seems to be related to the tachometer and the ABS light. If the tach fails, its a guarantee that the A/C doesn't blow cold and the ABS light comes on. So at this point, I'm just focused on getting A/C to blow cold in this Texas heat. I did the KLIMA jump trick between pin 87 and KL and the compressor comes to life. That's great, but this doesn't solve the issue, correct? I'm guessing I will need to check out the EGR to make sure I'm getting voltage to all connections. I'm new to this, so any input is greatly appreciated!

[sixto]

Don't leave the compressor engaged all the time to prevent damage if the evaporator ices; however unlikely in Texas this time of year. To have basic AC function while investigating Klima inputs, use an ice cube relay based on this diagram.

Sixto
87 300D^2

[Doktor Bert]

Bumped for informational value

[dennislarock]

Originally Posted by Chris_87_300D

Fantastic info on this thread and forum. I spent a few hours diagnosing the problem as per Brian Carlton's great info (posted elsewhere) and the info above. Ultimately, on my 300K+ 87 300D it turned out to be the Klima relay. I'm competent in soldering and, in hindsight, the process below is what I'd do first if my A/C compressor clutch wouldn't engage because it's an easy, quick procedure (my apologies as I'm a bit long-winded). If you're not comfortable/competent in soldering or have equipment, ask someone who is to help you.

- Remove the Klima unit (which consists of at least 2 relays and multiple electronics mounted to a circuit board inside the black case)
- Carefully open it (a small screwdriver on each of the long sides at the bottom lifts the large cover off the base). Mine had no glue or sealant, I might think twice if it did since this is a rather expensive part to replace.
- With a magnifying glass, look for bad solder joints. In my case, the bad joint was where the metal case of the relay controlling the compressor is soldered to the board - bridging pins 5 and 7 when called for. This relay is one of the two small metal boxes w/ a coil and 1 or 2 contacts each, mounted to the Klima board. The joint is located very close to the bottom of the board, near the "plug". Note: In my case it was visible but it is possible that this could happen within the bubble of solder and not be visible - you may wish to resolder at each of the places where the relay housing.
- As was the case above, I'd expect that the most likely place for a bad solder joint is one of the four places where one of the two relay "housings" (which acts as part of the electrical path) are mounted to the board. This is because it is very difficult to get the large metal case hot enough when soldering (at the time of manufacture) to get good mechanical adhesion of the solder.
- When repairing, hold the soldering iron on point of the metal case of the relay that protrudes through the board and touch the solder "wire" to the side of that metal (not to the soldering iron) until it melts to a nice tidy pool with the PC board contact. This ensures that the metal of the relay case is hot enough to melt the solder and you will get a solid mechanical bond of the solder between the relay and the circuit board. It shouldn't take more that a 5 seconds or so to get it this hot - if it does, your soldering iron isn't powerful enough and you risk damaging the relay or board with the prolonged but inadequate heat.
- If you can't see the metal of the relay poking through, you may need to get the solder hot whereby it will probably move away from the "cold" metal of the relay housing and expose it. Alternatively, you may need to remove some of the solder before repairing with either a solder braid or "solder sucker".

Effectively, in my case, the solder just surrounded the metal point of the relay (without true mechanical adhesion) and, over time, vibrated enough that it carved a tiny airspace between it and the solder of the PC board. At this point the compressor clutch could no longer be engaged.

Hopefully this will help somebody - best of luck!

Well my 5th KLIMA crapped today... so luckily I found this. Fortunately, I have a really good soldering setup ...Lionel Trains being my other addiction.


Thanks Chris!


Rock ON


dennis

[carock]

My 85 300CD needs the tach operational for the Klima to allow the compressor to run. If idle speed is too low the compressor turns off.

[vwnate1]

Subscribed .

[oilslick]

I replaced my inoperable KLIMA relay with the “ice cube” relay fix, but now I do not have the kickdown function for my transmission. Suggestions?

[Dankly1]

Great info in this thread!

For those of you with an 85 300D, there is an EGR controller behind the right side kick panel. I found a YouTube video a while ago that shows how to jumper across that connector to bypass the EGR controller and get the tach and AC working again. Here are some pictures of what I did to mine. After driving around like this for a few days, I spliced the wires together for a more permanent fix. The EGR controller is now undergoing "testing" in the bottom drawer of my toolbox.

Cheers!
Alex

[barry12345]

This thread should become a sticky?