Aircon not working (intermittently) - HCV??

[fefu17]

Hi, just got my puma back on the road after 3 years in the lock-up. It's great to have her back but these couple of days I've experienced an intermmitent problem in the aircon.

Most of the times, the aircon is working fine throwing ice cold air. However a couple of times, although I heard the a/c switch kicking in, it just threw boiling heat. I thought it could be the HCV.

What do you think? Have anyone experienced the same problem?

 

[Ian G]

Panel or HCV failure can give you uncommanded heat.

You want to see 12v (or battery voltage whatever that is) on the HCV plug at cold.

If you have that and its steady then the HCV is inoperative.

If you don't have that or its not steady then the potentiometer in the panel is noisy.

You should also have a steady 0v at warm and a steady pulse between 0v and 12v at points in between. Anything other than that is a dicky panel.