Fan switch problems

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Jan 5, 2015 | 08:13 AM

Johnny Be Cool

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Fan switch problems

1999 F350 Crewcab 4x4 dually V10.

Fan switch only works on High.
All fuses and relays look Good.
Is it a bad speed control switch?
What can it be?

Jan 5, 2015 | 11:07 AM

droldsmorland

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Joined: Nov 2011

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From: Land of Taxes

The blower motor resistor PCB is shot. "High" is the default when the boards blown. Not sure where its located on a 99 but likely around the blower motor. Purchase the part then look for it under the dash. <$20 part.

Jan 5, 2015 | 05:22 PM

projectSHO89

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From: St Louis

Both the blower motor and the resistor pack is under the hood on a Super Duty.

Jan 5, 2015 | 06:15 PM

4x4sd

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Joined: Jan 2015

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From: cookeville, tennessee

ck the connector to the resistor too... it may be melted

Jan 5, 2015 | 06:20 PM

Johnny Be Cool

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Connector looked OK, I picked up a resistor at Autozone for $15, now I need to find the time to put it on. Its located under the hood attached to the blower, shouldn't be that hard.
Thanks Guys!!!!

Jan 6, 2015 | 08:55 AM

droldsmorland

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From: Land of Taxes

Welcome. Be sure to close the loop here if it was the fix. It helps when others search for the same problem.

Jan 7, 2015 | 09:02 AM

Johnny Be Cool

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Tried to install it in freezing cold weather yesterday, but was unable to bet a good hold of the bottom screw. Once I replace it and confirm it's fixed, then I'll close the loop.
Thanks for looking?