A/C fan speed issue

Anyone else have an issue when they have the A/C on that the fan speed will blow faster and then slow down. Mostly notice the adjustment in speed when accelerating but it does it often just randomly. Thanks for any replies!

 

Do you have the automatic A/C and is it set to Auto?

 

yes I do and it is not set to auto

 

The only time I have seen electric motors do strange things while driving is when the alternator was overcharging. You might check to be sure it is not charging intermittently above 14.5V

 

Thanks for the reply I'll have to give that a look.

 

Try manually adjusting the fan speed to see if it stops. Based on the below, it's possible for the auto mode indicator to be off but some functions to still be controlled automatically. For example if you changed the flow direction the auto light would turn off but the fan speed would still be automatically controlled.

Or, hit the off button, then manually adjust the fan speed.

I didn't have mine two days before I quit using the auto system because it randomly adjusted the fan speed. The attached file explains how the system works. In there you'll see the 'neural network' controlling fan speed.

 

I wonder if the auto is pwm. Actually I’m sure they all are.

 

Thanks for the reply Homiec. I will have to give this a try to see if it solves my problem.