The a/c on my 2000 will engage at #1 speed on cabin blower but the green light and clutch go off on 2,3,4. I have checked the print and it looks like one of the resistors in the blower resistor assembly would be the cause. The curious thing is if that resistor ( between l/y & l) were open the blower would not run either. Any help would be appreciated and info on the phyiscal location of the resistor assembly.

 

I don't know where the blower resistor lives in your car. Doesn't position 4 go direct and not through a resistor? I know there is a relay under the hood for the blower on the passenger fender.


Have you eliminated the switch on the dash as the possible culprit, too?

 

I am having the exact same problem with my 99 Miata..

Anyone have any ideas?

 

The blower resistor is the culprit. Remove glove box (2 screws) Blower resistor just underneath attached to blower motor with 2 more screws. 3 plugs and good as new. Ordered resistor from advance auto online, use code P20 at checkout (saves 20%) should be about $28.00.

 

Well, there you go. I didn't realize the resistor opened the circuit for the clutch, too.