300E Auxiliary Fans
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Junior Member
Joined: Aug 2005
Posts: 65
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From: Boston, MA
300E Auxiliary Fans
I'm having issues with the dual auxiliary fans on my '92 300E with the M103 and would really appreciate some help troubleshooting. My problem is that both low and high speed are inoperative (I've read and tested every possible scenario for them to turn on) but I suspect for multiple reasons. I've researched the fan issues to death on this forum and a couple of the others and feel like I've almost got it...
Low speed. I jumped the wires connected to the red A/C pressure switch and the fans come on low. Does this indicate the switch is bad and/or the pressure is too low? Fans NEVER come on otherwise (i.e. using A/C).
High speed: Fans do not come on and coolant rises past 105C. I disconnected the wires from the temperature sensor on the block and jumped them. Fans do not turn on but I hear clicking from the relay. What's wrong?
Thanks
Low speed. I jumped the wires connected to the red A/C pressure switch and the fans come on low. Does this indicate the switch is bad and/or the pressure is too low? Fans NEVER come on otherwise (i.e. using A/C).
High speed: Fans do not come on and coolant rises past 105C. I disconnected the wires from the temperature sensor on the block and jumped them. Fans do not turn on but I hear clicking from the relay. What's wrong?
Thanks
