Blower motor stays on with key off. Could it be the resistor?
Dec 8, 2018 at 8:39 AM
Blower motor stays on with key off
2002 FORD F-150
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Good afternoon,
It sounds like the bower resistor is shorted high and keeps allowing voltage to the blower.
The heater blower motor switch resistor has the following features:
^ The assembly is located on the passenger side of the plenum assembly behind the glove compartment.
^ Three resistance elements are mounted on the resistor board to provide four A/C blower motor speeds.
^ Depending on the heater blower motor switch position, series resistance is added or bypassed in the A/C blower motor circuit to decrease or increase A/C blower motor speed.
^ An overheating protective device (thermal limiter) will open the resistor coil circuit when the temperature reaches 121°C (250°F), interrupting the blower motor operation in all speeds except high.
^ The thermal limiter cannot be reset and is not serviceable.
Below is a picture of the resistor.
You can get it at any parts store.
Roy
It sounds like the bower resistor is shorted high and keeps allowing voltage to the blower.
The heater blower motor switch resistor has the following features:
^ The assembly is located on the passenger side of the plenum assembly behind the glove compartment.
^ Three resistance elements are mounted on the resistor board to provide four A/C blower motor speeds.
^ Depending on the heater blower motor switch position, series resistance is added or bypassed in the A/C blower motor circuit to decrease or increase A/C blower motor speed.
^ An overheating protective device (thermal limiter) will open the resistor coil circuit when the temperature reaches 121°C (250°F), interrupting the blower motor operation in all speeds except high.
^ The thermal limiter cannot be reset and is not serviceable.
Below is a picture of the resistor.
You can get it at any parts store.
Roy
Image (Click to enlarge)
Dec 8, 2018 at 9:02 AM
Forgot to mention this truck has automatic climate control. Where they say the resistor should be it is not there. There is an air tube with a hose that goes back toward the center of the dash.
Dec 8, 2018 at 11:25 AM
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The part number does not specify any difference with auto climate control.
It shows it to be behind the glove box on the case as in manual controls.
Roy
It shows it to be behind the glove box on the case as in manual controls.
Roy
Image (Click to enlarge)
Dec 8, 2018 at 11:36 AM
Everybody I have talk to seems to think resistor is built into climate control due to it is not on the blower housing and the presence of the housing and the hose running back to center of dash. It looks factory to me.
Dec 8, 2018 at 12:50 PM
It is not part of it. It is a separate part.
Do you have the production date off the left front door?
Roy
Do you have the production date off the left front door?
Roy
Dec 8, 2018 at 12:58 PM
Not at the truck right now but I think 10/02.
Dec 8, 2018 at 1:17 PM
It is registered as 2003 but has 2002 instrument panel. We know this because the instrument panel has the 2002 motors for the gauges. Had to replace speedometer motor.
Dec 8, 2018 at 1:22 PM
Okay, if that is the date, it is a 2003.
All the information is the same. You need to look around more around the blower motor as it has 5 pin connector.
Roy
All the information is the same. You need to look around more around the blower motor as it has 5 pin connector.
Roy
Dec 8, 2018 at 1:22 PM
Okay. No wires except for the blower. Thanks
Dec 8, 2018 at 1:28 PM
You are welcome.
Roy
Roy
Dec 8, 2018 at 1:30 PM