A/C idler pulley

[fordgirl]

1995 f150 5.8L 250k

In park or drive, When my heater is running I can hear a click (which is the idler pulley starting to spin) and my RPMs jump up from about 700 to 1500 then another click (with the pulley stop spinning) and the RPMs go back to 700. Only lasts a few seconds, does it about every 30 seconds. Is this normal? Never did this before.

Thanks!

 

[Fellro]

Not the idler, but the A/C pump. It should only kick on at the defrost and a/c positions. Sounds like may be low on charge.

 

[dustybumpers]

Yup. Roger hit this spot on.

 

[fordgirl]

Ok so after some research, I am referring to the AC clutch engaging and disengaging randomly. It is supposed to be on the whole time the A/C is on?? Because it's definitely not.

 

[Fellro]

It is controlled by pressure and thermostatic control. It is supposed to run most of the time when requested, and since it doesn't, it indicates that the charge level of your a/c system is low.