heater only works on high

[93blueblazer]

i have a 99 cavalier 2.2L at trans. the blower fan for the heater only works on the highest speed. if you turn it down at all to a lower speed it just stops blowing. im not sure if it would be the switch or maybe something else. i know there is some part behind the blower fan that has to do with the fan but im not sure if it would do that. any help would be great.

[Airjer_]

Sounds like a blower motor resistor. Check for continuity between the pins on the resistor that the orange wire and the black/white wire go to. If its open than the resistor is bad. High speed bypasses the resistor and is grounded through the switch.

[PlanetDude]

Agree with Airjer - blower resistor. I had the same problem in the sis-in-law`s 96 Cavy, and the blower resistor was the problem.

It`s in a god-awful place (at least it was on the Z24), way back behind the blower motor on the passenger side. I seem to recall taking hte blower motor out to do it, may or may not be required.

It`s a weird size socket required too. 3/16? 5/16? I can`t remember, it was over a year ago.

Good luck - if you have any questions, post back - I`ll try and help.

[Airjer_]

Originally Posted by PlanetDude

It`s a weird size socket required too. 3/16? 5/16? I can`t remember, it was over a year ago.

Its a 5.5mm (yup a 5 and 1/2 mm socket). Sears carries them now if your looking for one.

[PlanetDude]

Thanks.... I know it was a weird one, out of my "specialty" socket drawer... I had 5 or 6 strewn across the workbench before I found one that would work.