There are different temp. switches. You can get one that comes on early or late. I went through all this crap a few months ago. There are a couple other things that could be wrong. But, I forget what they are. Do a search or click on my name and "find all posts by snookwhaler". It is in there somewhere.

What I did was ohm out the switch on the car to test it. Then I removed the switch from the top of the drier (You can remove the switch without losing freon). I heated some water in a pot and with a thermometer and suspended the tip of the switch in the water. As the temp. rose I was watching the water temp. and the ohm meter. It did close eventually. But, it had to get pretty hot.

You can use a switch that comes on earlier. IE: a cooler temp.

I know on the 85's there is a switch up on the thermostat housing that turns the Aux. fan on when the engine gets too hot as well, and in conjunction with the temp. switch over on the drier. I'm pretty sure your 83 has both as well. There are wiring diagrams involved here too. That is where I found most of the answers.

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AJ

1985 300D (SOLD)