Sam, I'll send you a private message. Thanks.

Hi there, what is going to happen when the klima relay fail? because my 95 E300D AC is start having the problem, the comerssor is on come on for two second once awhile, sometime I didn't hear it come on for the whole day, and also when the comperssor is not on, the it'll blow hot air instead of just wind, someone told me to run a new wire from the klima relay to the AC speed sensor, where is the AC speed sensor? can someone help? Thank You!

Well, the Klima/Kickdown Relay on the 95 E300D is more like a small circuit board, so I suspect that depending on what actually fails, there could be some variety in symptoms. However, I don't think this is a part that goes very often at all so I would suspect something else. You can check it out - you should be able to locate it from the info here - if not just ask. When I called Phil and asked him about the part, he said that he hasn't sold one of these before. Just so happens that someone had installed the one on my car upside down causing it to hold moisture and deteriorate. Check the wiring leading to the compressor (I removed the fuel pump pulley to get a better look at the AC compressor) - this model is notorious for wiring harness failure - it becomes brittle over time and falls apart - could be something shorting out. You can also check you compressor clutch by running 12 volts from the battery to the clutch (as previously suggested here). If you're not sure how, just ask.

Thanks Tankowner, I had own a 81 300sd also, the wire to the sd compressor is much easy to get to, but for the E300D all I see is the three wire (red, white and Blue) plug to the compressor, and I check all three wire has no voltage (the car is running and AC switch on), which wire I should put 12v to it? I knew the owner before me had put the new compressor on it, but it doesn't help, when I just bought the car, haft the time I got the compressor on, but now just like never had AC in it. Thank you for the help.

A/C (AND the dreaded KLIMA [and varients] )
 

Tankowner,

These guys in Sweden apparently have one.(I just "Googled" the part #)



Mr. Wood,

One of those three wires (to the A/C compressor) should supply 12V to engage
the Compressor...BUT only if the parameters of the KLIMA are met... I.E.: Engine Temps O.K.,
Refrigerant pressures AND Temps O.K.,Compressor Speed
matches Engine RPM within certain +/-,Etc.

What someone is suggesting is that you circumvent the Klima's protection of
your serpentine belt...(Compressor Locks UP... Belt snaps...Water Pump Stops
Turning...Your Engine "Cooks OFF" due to overheat) and "HOT WIRE" 12V to
the A/C Compressor directly...NOT A GOOD IDEA!

Oh Yeah, The Klima(Or Varient) shuts off the Compressor when you press all
the way down on the accelerator pedal(Kick Down Switch).

Thanks for checking. It's not that I can't find any of these Klima/KD relays, it's just that I don't want to pay a ridiculous amount for one. I know there are some just sitting out in a junkyard waiting for me. I have talked to a couple yards that say they have them, but again it is about $100 for a used on (double for new). I have talked to another member here who believes he has one to spare, so I am just waiting to see about that.


I believe they were just suggestig that I test to see if the clutch was functioning as a way to rule out a bad clutch. If you put 12 volts to the compressor clutch and it engages (you can do this without the car running) then chances are your clutch is not your problem. If you hit it with 12 volts and it snaps right onto the compresor hub then you are probably good. If it doesn't or it is sluggish in getting there, you could have yourself a worn out clutch. Compress ignite is right that you don't want to just bypass the Klima/KD and hot wire the clutch permanently - for the reasons that he mentions. But you can test the clutch and even start the car up and test the AC to make sure it is blowing cold when the clutch is engaged. I also used it as a means to get my clutch to engage so that I could hook up a manifold gauge set and test my pressures to rule out other potential problems.

If you are looking down on the compressor, those 3 wires come together into a female connector that plugs into a 3-pin male connector. I pulled the fuel pump pulley off to make it easire to get to. If you do this, be sure to loosen the 3 bolts on the pully before you loosen the serpentine belt. Then remove the belt and take off the pulley. Now you should be able to see the connector pretty clearly and get your hand down to it. Pull that female connector off (it's kind of a pain, you have to pinch in the sides real hard - i actually had take out the 2 screws holding the connectors down so that I could get a better angle on it). Anyway, once you manage to get the female connector off you will be looking at three pins. You will also see two wires coming up from the clutch coil - one goes to a ground that is visible and the other goes to the 3-pin connector. If memory serves me right, you want to put your 12 volts to the first pin - that is the one on your left if you are facing the engine (or the passenger side). If you clutch is working it will snap right in.

If your compressor has been replaced this might differ a little - I don't know about that. The red, white and blue wires doesn't sound like the color wires I was seeing, but then again, the insulation on my wires is all falling off right there - i had to tape them all up. Let us know how it goes.

Good discusioon. Now that I have the engine sealing properly, I have an A/C issue to square away. Seems it goes high pressure after running for a bit and shuts down.

And guys, do your 95's leak H2O when the A/C is on. I had the drains cleaned out, the evap was new(er), but I never get a puddle? I'm thinking the mechanic TOLD me they cleaned the drains. He said the evap was a replacement. ??

Wood,

If you aren't getting any voltage in those lines when the car is on and AC running, the problem is more than likely up stream. Check the clutch if it gives you peace of mind though. If you need a wiring diagram, let me know and I'll get you one - maybe we can post it here too. Also, if the PO put a new compressor on then you could also be looking at some subsequent fall-out from that - who knows. If you have a manifold gauge set, you ought to hook them up and see what you get when you have 12 volts on the compressor clutch. You'll find your problem sooner or later.

I can't think of a better way to spend the day. I wish I thought of that.

Thanks again Tankowner, just find my way to take off the 3 wire plug, and put 12v to the clutch and it work fine and the cold air start to blow (but once I take off the 12v, don't know why the HOT air is blow instead of just wind), what should I do to check what else is wrong, or should take it to shop?

Wiring Diagram may be helpful, Thank you for your help!

Take it to the shop? Don't get crazy on me wood. You're knee-deep in trouble-shooting now.

So, even though I said that it is not likely to be the Klima relay, that doesn't mean it isn't. In fact, since I made it a point to say that, then it probably is. You'll want to take a look at it. It is located behind the battery. There should be a black plastic shield behind the battery - it comes out pretty easily. Behind the shield are various relays and the Klima relay is up front. Look back at post #13 for the picture of it.

Getting it out is sort of a pain, but not too bad. You might want to pull the battery to give yourself more room to work. If installed correctly (unlike mine was) the part number (see pic) will be facing up. The relay has two rows of male connector pins. I don't recall exactly how I got it off, but it involved using a flat screwdriver. Once you have it out, the black plastic cover on the actual relay can be pried off to get a look at the internal electronics. You might want to take a look and make sure it looks alright. I still need to post a picture of mine - what a mess.

Here is the AC wiring diagram. It prints out in several pages. I just lined them up and taped them together so I could see the whole thing at once. Handy coordinates on the X and Y axes help you identify components. Good luck!