89 560SEC blower is running fine and suddenly dies. Checked fuses... all seem good, removed and checked connections on relays, some dirty, cleaned and reinstalled. Still will not blow.

Checked strip fuse, (next to fuse box and plugs into a socket like a relay, has 2 30A fuses), checked all fuses for power thru, still no power to fan motor. Used volt/ohm meter and have the lesser voltage at fan connection but no 12V. Did blue wire ground scenario, no fan. Everything now says switch to me. How do I remove and troubleshoot switch. Where does the voltage to fan speed switch come from? I hear everything energizing when climate control is turned on, no fan. Everything everyone has come up with so far has been in great detail and really makes the troubleshooting easy. Wiring direct to battery and running ground to blue wire connection blower blows great. HELP ITS HOTTT!
Thanks
Steve

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80 240D 440K (sold)
82 300SD 289K (sold)
85 300SD 295K (sold)
84 300D Turbo 188K (sold)
89 560SEC 135K (sold)
88 300SEL 139K (sold)
85 300TDT 146K (sold)
90 560SEL 127K "Black Moose"
89 300SEL 115K "Big Moose"
79 450SEL 145K "Old Moose"
84 380SL 103K
81 380SLC 145K
99 C230Kompressor 105K

<< and have the lesser voltage at fan connection but no 12V. >>

Where did you get this??

I was told it has to do with variable speed control voltage. It comes from the connector where the fan motor hooks up.
Thanks
Steve

__________________
80 240D 440K (sold)
82 300SD 289K (sold)
85 300SD 295K (sold)
84 300D Turbo 188K (sold)
89 560SEC 135K (sold)
88 300SEL 139K (sold)
85 300TDT 146K (sold)
90 560SEL 127K "Black Moose"
89 300SEL 115K "Big Moose"
79 450SEL 145K "Old Moose"
84 380SL 103K
81 380SLC 145K
99 C230Kompressor 105K

Control for the blower also passes through the ACC pushbutton unit, which is famous for developing solder/trace cracks. Later revisions have an additional fuse at the back of the unit, which could have blown. Cheers, Andrew Seidel.

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86 560SEC
85 500SEC Lorinser
83 300D Turbo
75 240D

Well the strip fuse was broken at one end and now the blower blows GREAT!!!!!!! My thanks to everyone who helped. I still have a small problem... The car cranks but will not start. Could this be from having the key switch on and off 2000 times while testing the fan? What a dork. My first MB that I have had to do electrical work on. Drag...

Thanks
Steve

__________________
80 240D 440K (sold)
82 300SD 289K (sold)
85 300SD 295K (sold)
84 300D Turbo 188K (sold)
89 560SEC 135K (sold)
88 300SEL 139K (sold)
85 300TDT 146K (sold)
90 560SEL 127K "Black Moose"
89 300SEL 115K "Big Moose"
79 450SEL 145K "Old Moose"
84 380SL 103K
81 380SLC 145K
99 C230Kompressor 105K

Finally, after checking every fuse and relay, etc and soforth the reason the car wouldnt start and there was no power to the fuel pumps was the 2 red wires that connect to the positive side of the battery. The smaller nut thats secures the two wires was loose and not making contact. Tightened up the nut and she started right up. Thanks to everyone who helped with my electrical issues. I now know 10 times what I used to know and that is 1% of what you guys know.

Thanks again

Steve Katz

__________________
80 240D 440K (sold)
82 300SD 289K (sold)
85 300SD 295K (sold)
84 300D Turbo 188K (sold)
89 560SEC 135K (sold)
88 300SEL 139K (sold)
85 300TDT 146K (sold)
90 560SEL 127K "Black Moose"
89 300SEL 115K "Big Moose"
79 450SEL 145K "Old Moose"
84 380SL 103K
81 380SLC 145K
99 C230Kompressor 105K