l searched for a while trying to find the answers to my questions, but I couldn't find anything entirely definitive. My questions have to do with my new to me 1992 190E 2.3 that I picked up for a mere $500.

The electromagnetic fan engages just like it's suppose to when I jump the connector for the temperature switch at the cylinder head (the one with 3 pins, two for fan engagement and one for the gauge). So, I ran the car and waited until the temperature rose to 110 degrees Celsius at which point the fan locked up and cooled the engine down to 100 degrees, then unlocked.

I was confused a bit by this because I thought that the electromagnetic fan was suppose to lock up at 100 degrees and unlock at 90 degrees. Am I wrong? If I am wrong and it's working correctly, then I'd like to add a resistor to the switch to make it cut in 10 degrees early.

Also, I noticed that the high speed auxiliary fan switch (or what I presume the high speed aux. fan switch is) does not kick in the high speed fan until 130 degrees! A little too late to help at that point in my opinion. Does anyone know which resistor I could add to the switch to lower the cut in point from 130 degrees to 110 degrees? The switch in question is light blue and located on the cylinder head next to the above mentioned switch. When I jump the pins on the connector, it turned the aux. fan on at high speed.

Another problem regarding the aux. fan is that it will run on high speed randomly, even with the light blue switch mentioned above unplugged. So, I figure the problem must lie with a relay or another switch that I don't know about.

Also, what is the purpose of the temperature switch on the water pump?

Sorry this is a bit long winded. Thanks in advance.

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1998 E320 Wagon

1992 300D 2.5 TURBO

1991 560SEL M119.960

1986 300SDL TURBO

1992 500SL Parts Car

1991 420SEL Parts Car