I have a 1999 EB Expedition with climate control system. I am getting warm air from the rear system, but the front is barely warm. I think the A/C is on at the same time as the Heater and is cooling the warm air. It has nothing to do with the blend door it is working perfect. Is there a way to keep the A/C compressor from working without damaging it?


Any help on this would be greatly appreciated, Thanks Carl

 

If the front system cannot overcome the effect of the A/C system, something is out of order on the heating side. Compressor operation is normal for most climate control mode settings.

 

If you take it off Auto and use Floor, then the compressor won't run. This should let you be able to see any difference, if there is any.

 

Doesn't the 1st gens have a AC button? Turning it off will inhibit the AC compressor?

 

Not my 99. Just the 7-8 position swivel switch for the front and the overhead swivel switch for the rear.

If turned on to defrost the a/c will be on but the heat level swivel switch will allow the air to come out very warm, both front and rear.

 

No and that's something that I find annoying. After all, why should I have to pay (in extra fuel) to run the compressor just because I want my defroster on, or the vent floor position! Not to mention the added wear and tear on the compressor. IMO, all vehicles should have a compressor switch and a recycle air switch...let the driver decide.

 

That is surprising, I've never seen a car without an AC button before if it has AC, my '05 has one as well.. hehe..

 

These are trucks, not cars.

 

Right, my bad...

 

My '01 doesn't have an AC button either. I'm pretty sure the only position the compressor doesn't run is floor/vent together, but I'm not certain.

 

Usually ford has them set up to run without the ac in panel and floor. But, If you select floor/panel split, it will run.

Every ford I've owned without an ac switch has been this way all the way back to my 81 crown Vic.

I'd be more suspect of a malfunctioning valve in the heater hose than anything else. Not sure if yours has one, but i know my 05 does.

I'd start there.

 

You could be right meborder. It's been a while since I've paid attention, and that could explain some of the loss in fuel mileage.

 

Thanks for the responses. I let the truck run and get hot, then put the heater on floor. The air was hot for less than a minute and went to Luke warm still puzzled.

 

Plugged heater core on the coolant side?


if the hoses aren't too hard to disconnect at one side or the other, back flushing them with a garden hose can work wonders if the core is getting blocked with sediment.

 

That is the exact time you need to check the temperature of the coolant hoses under the hood. If the inlet is still very hot but the outlet is lukewarm or cool, there's almost no flow through the core.

Possible causes, if a wide temp differential is noted, include:

Low coolant
Clogged core.
Other restriction in the heater coolant loop.
Worn out water pump.