Bad Blower motor??
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Freshman User
Joined: Jul 2004
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Bad Blower motor??
Recently I lost the capability to adjust the fan speed on my heat/ac blower. I now only have either off or high. Nothing in between. Do you think it is a bad blower motor or somethin gwith the controls? It is on a 93 F-150.
Thanks in advance.
Nate
Thanks in advance.
Nate
Elder User
Joined: Sep 2004
Posts: 941
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It's not the blower motor if full speed works. Ford's blowers are simple DC motors. They use dropping resistors, usually inside the air plenum, to supply a lower voltage when the controls are set for less than full speed.
Oftentimes the connections to the resistors get corroded and a simple emery paper cleanup will get things going.
Or the controls or wiring might have an open circuit.
Oftentimes the connections to the resistors get corroded and a simple emery paper cleanup will get things going.
Or the controls or wiring might have an open circuit.
Junior User
Joined: Sep 2004
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From: south west of Germany
Hi,
i think it´s the switch, because the blower motor, works ... it is just the adjustment switch.
Remove the ****, then the electrical connector of the back, loosen the screws and you can replace the switch.
Andy
i think it´s the switch, because the blower motor, works ... it is just the adjustment switch.
Remove the ****, then the electrical connector of the back, loosen the screws and you can replace the switch.
Andy
FTE Chapter Leader
Joined: May 2002
Posts: 42,594
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From: Fraziers Bottom, WV
Look on the outside (under the hood) of the heat/AC box on the firewall. You will see the motor and beside it and below the motor will be a 3 wire plug. This is a resistor that controls the speed. One side is most likely bad. Poll the plus and remove the resistor by removing the 2 screws and see if one side is bad. It will be obvious! The switchs do fail but not as often as the resistor.
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Freshman User
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That was it! I pulled out the resistor and one terminal was melted right off. Looks like I will be off to the salvage yard to get a new wire harness/connector to splice in. The connector was melted and very difficult to remove. THanks! It will be nice to finally have control of my heat, since winter is coming!
Nate
Nate
