Got an 85 300 D with a possible bad klima. All other problems are sorted out with the A/C so this is the last "weak link"

Does anyone know the proper procedure to test this before I spend way too much money on a new one??

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1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair

Here's one approach:

Dear God, is there a way to determine if this problem is the Klima or not?

Use SEARCH facility - key in KLIMA and Titles Only. Many hits

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

I have been searching for HOURS. Yes I use the "search" feature BEFORE I post a question. Most of the threads are NOT relevant to my specific delima.

I need to know how to test the Klima on my 85 300 D.

The pin numbers etc change from year to year.

__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair

Would be happy to fax that test! Leave that fax number here or send me private message.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Hey MB DOC,

My fax number is 206-237-7390

The pins on my Klima part number 001 545 74 05
'85 300 D

87, 15, 31 on one row
KL, 87k, VL, GM+ on the other row

Thanks so much for your help!

__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair

The only true way to test is to replace. I had bad solder connections on my board, resoldered but it still would not work so I bought new and wala its working.

To test:

Pin 31 is ground
pin 15 is B+ 12V when ignition is on
pin 87 is out to compressor.

KL ? Speed
87K ? speed
VL ? climate control
GM+ ? engine speed
Not sure which is which but I do know that you have a speed reference signal from your speed sensor in back of the compressor on 2 of those pins. One other is connected to your engine speed reference signal on mine its "TD" and the last is from your climate control module.

To test Kilma;
Remove and jump 87 and 15 and see if compressor comes on. If compressor not on check fuses, wiring and connections to compressor. If so then check signal from speed sensor should be 0.2~0.4Vac across the 2 wires coming from the sensor not ground. Check speed sensor. You also have a microswitch somewhere under air cleaner box connected to the throttle linkage, it is used to cut off compressor when you give full throttle.
If all checks ok I would open relay module and check for bad solder connections. This is a common problem.

My first posting - hope this is correct - but Dieselgiant, what else have you replaced in the entire A/C system? I'm struggling w/ a similar problem (new compressor, new controller, good gas pressure) but still no compressor "on".

That would be a sweet noise to hear right now. Any info is appreciated.