AC only in all setting/temp ranges

[762mm]

Hello,

I have a 99 XLT SOHC and today, after a radiator/overflow tank drain & refill with new Prestone mixture, I noticed that my heater doesn't work anymore... All I get is cold AC air blowing out the vents no matter where I position the temp gauge (cold/hot) or the vent setting knob (the vents seem to work well though, and I can switch between AC and MAX AC, but that's all that's available).

I ran the vehicle for about 15 minutes on idle and with the heater on the max position before noticing that (in order for new coolant to enter the system). If you would happen to know what this might be, please let me know... I read about the blend door problem, but since my AC works fine (and it's the only thing that works), I guess it might be something else. Any input would be greatly appreciated, thanks in advance.

 

[762mm]

A little update on the situation.. The heater started working again, but the AC compressor won't shut off, therefore I get heat and AC at the same time.

Could this be caused by the blend door, or is this something else ? Any help would be greatly appreciated. Thanks.

 

[RiverRat]

Turn the vent selector to "panel" and the a/c shouldn't be operating.

Also, when you flush the coolant it helps to keep the temp selector on max heat to help get the coolant flowing thru the heater core.

 

[762mm]

Turn the vent selector to "panel" and the a/c shouldn't be operating.

Also, when you flush the coolant it helps to keep the temp selector on max heat to help get the coolant flowing thru the heater core.

The AC doesn't shut off no matter where the selector is at. Now I have the AC and the heater operating at the same time.... I really need to solve this little big issue, because winter is just around the corner and temperatures below 30 C are common here in eastern Canada. Any suggestions are more than welcome...

 

[RiverRat]

I've never seen that. First thing I'd check is that the a/c clutch isn't frozen to the compressor. Does the a/c compressor cycle? Turn the engine off and see if you can turn the a/c clutch while the pulley is stationary.

 

[cdsl227]

I know on the 01' the A/C runs in all settings except when you set it to push only from the floor (I think it's one setting to the right of off), but it kicks on and off periodically.

It says that's normal operation in the owners manual.

 

[762mm]

The AC compressor does engage every minute or so (I can hear the "click" typical of that from the engine, plus the condenser tank gets cold & "sweats" after driving the car with the heater on), but I never noticed that before, maybe because I never paid attention to that... Could it be that the AC is always running on these trucks even in winter when you only need your heater ?...

 

[cdsl227]

If you have the manual for the truck give it a quick read, in mine it states that's year round normal operation. I noticed that back when I had an LTD, hell I think even my Econoline and Montego worked the same way...

I know there was a reason they do that, but I just can't think of it...

 

[762mm]

If you have the manual for the truck give it a quick read, in mine it states that's year round normal operation. I noticed that back when I had an LTD, hell I think even my Econoline and Montego worked the same way...

I know there was a reason they do that, but I just can't think of it...

Yes, after checking with the user's manual, it would appear that the AC always works in most modes as long as the temperature is 10 C or above in order to de-humidify the air that comes out of the vents. It is the first time I notice that, and I just think that it's plain stupid for Ford to have incorporated that into the truck (their overall fuel economy would be way better with no forced/permanent AC operation). Thanks for the answers though, it is much appreciated.

 

[cdsl227]

Yes, after checking with the user's manual, it would appear that the AC always works in most modes as long as the temperature is 10 C or above in order to de-humidify the air that comes out of the vents. It is the first time I notice that, and I just think that it's plain stupid for Ford to have incorporated that into the truck (their overall fuel economy would be way better with no forced/permanent AC operation). Thanks for the answers though, it is much appreciated.

Yeah it is a killer on fuel economy. I think some people just pull the little 2 wire clip off the compressor to get around it in the winter then pop it back on in the summer for the pump to work.