hello, i own a 1984 300 cd and the temp is going way past 100c. when i turn the a/c on the aux fan turns on the way it should. when the a/c is off the fan never comes on. i have checked the fuses, and also grounded the single wire that goes to the sender above the thermostat housing. this single black wire has juice when tested with a test light. is this normal? any ideas? thanks for any help!

Suggestion: you might try posting in the Diesel Discussion subforum. I'm a short-time 300D owner, and as such won't presume to best be able to answer all your questions, but the collective experience there is substantial.

Before doing so, I would recommend that you spend a little time using the forum search function to search existing threads in the Diesel Discussion. Any number of people have been down the "running too hot" road, and will have dealt with the same sort of troubleshooting issues.

It also might help if you could provide some more details, i.e., does it do this at idle, or only under heavy load, or only when the AC is running? Did the problem occur abruptly, or is it something that has been gradually getting worse over time? Any maintenance or repair history for the car? How high is "way past 100" (opinions vary on how hot is too hot)?


-- eskimo