A/C fan will go from a relatively high level to essentially stopped

LRMCNEIL

MEMBER
2003 FORD F-150
V8
2WD
AUTOMATIC
130,000 MILES

I have noted that occassionally, the A/C fan will go from a relatively high level to essentially stopped - while the A/C is still bringing the temp down. After a few moments, it starts again and delivers good air flow. The compressor seems to keep running - it's just that fan speed drops greatly for a short time. Happens anytime - driving at speed, idleing, etc.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

More than likely you have a resistor or blower motor issue. We need to check the voltage at the blower motor when this is happening to see if the voltage is dropping. If it is then the resistor is the issue. If it is not then the blower motor is the issue.

Here are some guides that will help with replacing the blower if this checks out:

https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only

https://www.youtube.com/watch?v=1eau7hCuuJ8

Below is the wiring diagram and the process to replace the motor. Please let us know if you have other questions and we can go from there. Thanks

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