My 87 300D turbo has started to have an intermittant tach and AC operation. the fan still blows but the cold only comes when the tach is working. Both will stop at any time and only sometime start after the car is restarted.

TNT

would be my first guess.

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I cleaned both Battery posts and the ground point and it was back briefly, but went away again. Fuses look fine.

TNT

Need pictures under hood, to evaluate possible issues.

Do a search under KLIMA relay

The Klima relay takes a speed signal from the tach. It compares this speed signal to the speed of the compressor and, if they match, it keeps the compressor engaged. If they don't match, as in your case, because there is no tach signal, the Klima will dump the compressor to protect the serpentine belt.

So, you need to track down why the tach signal is intermittent. When you fix this, the a/c will function properly.

It has nothing to do with the Klima directly. The Klima is simply not getting a tach signal.

If you can't fix the tach signal, there is a way to bypass the Klima via the use of a cobbled up ice cube relay. I just did this myself, today, to eliminate the Klima from the entire diagnosis.

I searched the site and found the Klima (wasn't he a hockey player for the Red Wings and Oilers) it took a while to identify it. So I cleaned it and all ground wires and then cleaned the area and all wiring around the AC compresser. I used an emory on anything not clean and shiny. After several tries and more tweaking tach and AC are working again, thank God as I am on vacation in the badlands of Alberta 100F (no multimeter, just battery post brush, brake clean and my wifes emory board)

Thanks again

TNT

How do I check the tach signal? she crapped out on me but gave me 42.5 mpg highway (Imperial gallons 4.54Litres vs 3.78liters US gal.) on my ride home

TNT