Heat/AC always blowing even when turned off?

[BrianDye]

My 92 x, when I have the heat, or AC on high, it really blows, better than my 97 taurus, and better than my moms 08 Escape (way hotter and colder too)



But when I turn the fan knob all the way up, like direction wise (to the off position) it still blows out, and its really noticeable, it'l warm the car up if its on hot, and cool it down if its on cold, i have to keep it on DEFROST so its not blowing at me, usually a window is cracked too.

Is this common? Am i doing something wrong? How can i fix it, its just one of those pet peaves ive had since i bought the thing lol.

Thanks guys

 

[BrianDye]

nobody?

 

[boggs1227]

hard to say ......

first guess would be to check your heater control valve under the hood and the vac line going to it ( near the air box where the heater hose's are .the valve is operated by a vac controled line that runs to a solinoid) when top slide control(in truck) is set to the first 2 settings (far left ) the valve should be closed (there is a pivit arm on the unit see if it moves via the heater controls in the truck )diverting hot coolant back to the radiator. sometimes the solinoid can go bad and the unit will be off so to speak and hot coolant will circulate trough the heater core because either it's stuck from rust or lack of vac pressure.other than that i would take the lower panle that attaches to the heater core and see if your blend door is malfunctioning .


hope this helps if any . . . . .

 

[Maniak]

The '92 doesn't come with a heater control valve, but you can add one. What it will do is keep the hot water out of the heater core which can help keep that always blowing air from getting near as hot. It also helps the a/c and in my tests, found it will let the a/c drop the temps another 5 degrees.

You can get a heater control valve for a 94 X and install it yourself. For a vacuum source I put a t in the vacuum line that helps control the blend door (down under/behind the glove box) and ran the line into the engine compartment where the heater control valve is (right at the firewall, where the heater hoses go into the firewall). Now when the a/c control is set to "max a/c" the heter core isn't getting hot water..

As to the other problem, outside air coming into the cab when driving.. Our '92 also has that issue. I've been trying to fix that off/on for years.. I've helped knock it down some by sealing the a/c box the best I could (outside portion).. It seems the high pressure air under the hood caused by driving was pressurizing the heater/ac box which would then push the air into the cab. We still have the issue and it is anoying, but not enough so for me to tear apart the heater box etc to see if I can get the blend door to seal better.

~Mark

 

[boggs1227]

oh wow ! , i learned something new today .

sorry for the heater control valve suggestion...i did not know the
92's did not come with them.