Trying to troubleshoot why my aux fan wont come on, the fan works when connected direct to a 12v source. The fan will not come on when the ac pressure switch wires are jumped, nor will it come on when the engine temperature wires are jumped.

I don't know if your car has this, look for a white ceramic resistor on the left front fender well near the LF frame horn. They can corrode and cause an open circuit.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Check fuse (IIRC #7), Continuity between the wires, sensors to fan. I believe there is also a relay.

For those whose first response is to start throwing darts, the score may be improved by first finding where the dart board is hanging; that is to say, what chassis is involved.

Is there another dart board in the 300SDL game hall other than the W126?

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer