I have a 2001 Explorer sport. When I turn the heater on now, the compressor seems to engage and disengage. Was wondering if anyone has had this same problem before I bring it in.

 

The A/C compressor is designed to run when you select Defrost , Floor / Defrost .

 

To further what Paul said, read your owner's manual under the section where it describes the operation of your heating/AC system. On my '97 the compressor runs in every position except for vent and off whenever the outside temperature gets above 50F. Ford changed the system slightly between a '96 and '97 though where the compressor also will not run in the floor only heat mode. On the '97 it does operate in this position. Ford might have gone back to the operation of the '96 systems on your '99 so I would check the manual to be sure. Your manual will say what modes your A/C compressor will operate in.

 

You're right, I wish It wasnt like this but, from reading the book it the AC is not on when the floor heat is selected. I was using the dash and floor setting, although, I am still wondering why in the world anyone would want the compressor to come on in the setting when its freezing outside. Thanks for the info.

 

Having the A/C on , a blend of colder air acts a a dehumidifier . Cooler air can support more moisture .

 

[updated:LAST EDITED ON 06-Mar-02 AT 10:14 AM (EST)]First off, your compressor shouldn't come on when the outside temperature is below 50F regardless of setting. As Paul said, to have it come on when it is in the 50s helps prevent condensation on the inside of your windows since the A/C compressor also serves as a dehumidifier. It is also benificial to run the compressor from time to time to keep it lubricated. The older systems that didn't run it with the heat could go many months between uses which would cause the seals to dry out and start leaking when the A/C was used again.

 

I have a 96 Explorer Sport Trac. The compressor comes on in DASH/FLOOR setting as well as the DEFROST & AC settings in 20 degree weather. I just got this Explorer a couple months ago so I'm not very familiar yet. I didn't know about the 50 degree sensor/switch (?or what ever?) and 20's is as low as we've had in Nebraska so far this fall.

I expected it be on in AC and DEFROST setting but should the compressor come on in the DASH/FLOOR mode? If not, what do I look at first?

Les

 

First, Ford didn't make the Sport Trac in '96. Second, on my '97 the compressor will come on in all settings except off and vent (face). Any of the heater or defrost modes will cause the compressor to come on when the outside temperature is above 50F per my Owner's Manual. I remember reading in the '98 Explorer Owner's manual though that Ford also added the feet only heater mode to when the compressor won't come on.

 

OOPS, it isn't a 96 SPORT TRAC . . . It's a SPORT with "control trac 4WD" Guess I should get to know my vehicle.

It didn't have an owners manual so I don't know what I should expect. But I was suprised to hear the compressor kick on in the FLOOR/VENT mode and I agree with HighPlainsD, why would one want the compressor on. I expected it in both DEFROST modes as well as A/C. I guess I will just accept reberhardt's reasons and move on.
Les