A/C Issue on 93 525

[Lilrobus]

Although there have been some discussions about A/C problems similar to mine, I'm still quite stumped.

About a month after having my microfilter replaced (at the dealership), the passenger's vents of my car simply blow hot air, and this takes a slight toll on the cold air that comes out of the driver side vents. Those in the back seat blow fine. Interestingly, the only time all vents will blow cool are in heavy traffic, especially If I'm at a standstill. Once the vents blow cool, I can drive as fast as I want - all blowing cool. I'f I leave my house and immediately get on the freeway, HOT air will blow out of the passenger side vents for as long as I drive. I sure hope someone can tell me WTF is up with this - I live in Texas and miss my cold air! Thanks a million!

[upallnight]

Servo which control the vent on the passenger side is not closing the vent.

[winfred]

it sounds like one of the heater valves is sticking, once it sticks it's generally crap and needs replacing you can play around with it but it's going to stick again, you can wack it with a hammer/block of wood/screwdriver handle and it may work for a little while, another thing to do is shoot power to it and work the hell out of it off and on, theres 3 pins in the plug and one closest to the firewall is the common pin and the left and right pins are for the left and right valves, hook one to hot and tap the other to ground listening for the knock as the valve closes, wack it till it knocks, then work it for as long as you feel like hopefully wearing down the crud that's making it stick open