Hello,

my 1986 300E is having issues with the aux fan coming on.

The large single fan is working. I tested it right at the fan connector.

I tried jumping the aux fan temp switch at the cylinder head and only the relay activates fan doesn't kick on.

I traced down the wiring to the coolant fan resistor and it literally fell apart in my hand.

The question is will this solve the issue of the AC compressor not kicking on as well as the high speed fan operation or is this a different issue?

Furthermore, the Resistor is NLA. will an m104 ballast type resistor work just as well?


Im trying to test the low speed fan operation at the temp sensor at the drier and receiver. Do I just apply voltage or will bridging the two wires suffice?
Car in the ON position?

Sorry for the lengthy post.

Thanks in advance.
Tibursky