I've got a 1992 300D 2.5 in which the compressor turns off. You won't belileve how excited I was to find a very detailed description of how to test the Klima relay. All I had to do is test pins 1,2,3...etc.

Then I pull my relay and the pins are marked GK, GK+, 87, 15, TD, 31, T, KL, 87k, VL, and gm+

Can anyone translate how I would number the pins 1 to 11 for the test procedure?

THanks
Jim Ragsdale

The pin numbers on the relay aren't the same as the pin numbers on the socket. They socket pins are clearly marked 1-12. Oh well......

Ok, I've narrowed my intermittent compressor to the speed sensor on the starter gear ring. I get twice the resistance and half the voltage as the thread suggests. I just can't believe it's bad since the compressor does work sometimes. Can anyone give me their thoughts. Otherwise, I'll just replace it. I just hate replacing parts if I'm not sure.

I do have a fuel leak between the #5 hard injection line and the injector pump I've been working on trying to stop but so far haven't been successful.

Could dirt and fuel grime cause this sensor to read incorrectly?

First, have you discovered the forum right below this Forum called "Diesel Discussion"? I just happened to click the wrong link and noticed some posts I thought I'd check out.

Second, .. . the most common reason for fuel leaks, or the first thing to wear out are the return lines which are made out of hose/rubber material. Over time, they get brittle and start leaking and pooling at the bottom of the head. I would suggest buying a length of the proper OEM hose, remove, measure anew, snip and replace. I would replace all of them, even if only one is leaking, as the others are sure to follow. Similar to replacing coolant hoses . . . [don't do like my ex-husband did and replace one at a time, one every month and having to pay the cost of coolant replacement each time.!!!!] Then do your normal bleeding of the system. Unless you observe the injector leaking, or a leak from a crack on the tubing, or crack on the tubing, I would say go straight for the return hose, especially if it's pooing below it.

As for the AC question, you are just as likely to get an answer in the Diesel Discussion Forum, even though the AC systems may be identical between the E and D models.
Sorry I cannot help you with that problem, but I would look for a reason for less power going to those wires, then replace the entire system. . . . sorry, just don't know enough about it.

Torie

__________________
1983 300D, the "Avocado"
1976 240D, 4-spd the "Pumpkin", SOLD to Pierre
1984 190D, 2.2L, 5-spd, my intro to MBZ diesels, crashed into in 2002

Since the compressor clutch problem is intermittent, the first troubleshooting step is to connect manifold gauges and confirm the refrigerant charge. When it is low, the low pressure switch interrupts the clutch circuit. If it is low, this will keep you from chasing your tail tracing the circuitry.

Also, as you have probably learned in your wiring, the speed sensor trips out the clutch in the event of clutch or belt slipping.

I pulled the Klima and checked the starter ring speed sensor and the voltage was half what I was told it should be and the resistance was over twice what they told me. I'm going to replace it and see if that works. Thanks,