Heating Question

[Jeff Harwanko]

Now that it is getting colder here in the Northeast, it is time to use the heat in the Trac. Recently, while at idle with the heat on in all positions except floor only, the air conditioning compressor cycles on and off in 2 second intervals. The clutch locks up for about one second every two to three seconds. At idle this puts a big toll on the engine. The rpm's drop and the lights dim (big electrical draw?). Please see the picture that shows all of the positions that this is occurring in. Has anyone experienced this? Any help would be greatly appreciated. I hate having someone else work on my vehicles when it is something that I can probably fix myself. Thanks guys![Broken External Image]:

 

[Jeff C]

I have this problem. Many members here will reccomend cleaning the IAC or checking for a cracked vacum hose in the engine bay. Both COULD be causes, but neither one solved my problem. The local Ford says it is operating normally, which I think is kinda strange since sometimes it stalls when I put it in park or neutral, and I experience the rpm drops you experience; I'm basically waiting for it to stall in an intersection so I can get t-boned and get some money from Ford. I'm not sure how it can be operating correctly when it didn't do this until last summer or so. :unsure:

 

[Wes Davis]

I don't know about all the settings but when ever you use a defroster setting (the last two) the compressor is designed to cycle on and off. This is to dehumidify your interior and keep fog from forming on your interior glass.

 

[Wes Davis]

I don't know about all the settings but when ever you use a defroster setting (the last two) the compressor is designed to cycle on and off. This is to dehumidify your interior and keep fog from forming on your interior glass.

 

[Jeff Harwanko]

Yes, that is correct. What is abnormal is that the air-conditioning is also cycling on and off in the positions that heat the upper torso and the setting that heats the upper torso and feet. Normally, I believe that it is only supposed to cycle when using the two settings that use the defroster.:unsure:

 

[Jeff Harwanko]

I just want to give a big thanks to everyone at this site! You guys (and gals) have been a big help to me. Because of you I have sucessfully...Installed a ipod interface, new shocks, uprgraded 04 brakes....(make sure you guys use the permatex brake lube...green goopy stuff...expensive, but works wonders), Upgraded to Monroe Sensatrac's, and I will be going to pick up my weather seals (for wind-noise) at lunch today. It is nice to have a group of people as into their vehicles as I am. Thanks again!

 

[Jeff Harwanko]

Just took the truck out at lunch.....Could the problem be in the switch itself ? Is is possible for vacumm to leak thru inside the switch....so that it thinks it is in defrost mode, even though it is not?

 

[Tom Schindler]

The reason the A/C cycles is to help remove moisture from the cabin to keep the windows clear.



It doesn't mean a switch is bad. It is working as it should.



If you are experienceing idle issues, you might need to check out you IAC valve.





Tom

 

[Jeff Harwanko]

Yes, but the A/C is cycling when not in defrost mode. It has not done this prior to this year. I do plan to clean the IAC valve this weekend anyway. Thanks for all of the info guys. PLEASE send any additional suggestions that you might have. Oh and by the way, the Trac idles fine when the heat is not turned on:wacko:

 

[Tom Schindler]

It only does not run in two positions. Read your owners manual.



It has always worked the way it does now, you just never noticed it before.





Tom

 

[Fer Echegaray]

Tom:

3 positions if you include "Off"...

 

[Jake Levin]

I had the exact same issue DE-Trac, I took it into the dealership (before I became a member here) and it was a cracked vaccum hose. Cost me $250 to have them replace it

 

[Jeff Harwanko]

Thanks guys....I will clean the IAC valve and check for vacuum leaks this weekend if I have time. I'll let you guys know what happens! Thanks again!

 

[Kevin Palmer]

Cayman is correct.

It operates in all but two positions, (not including off).

 

[Tom Higbee]

THIS PROBLEM HAS BEEN DISCUSSED BEFORE ON THIS SITE. THE COMPRESSOR NEEDS A CERTAIN RPM TO RUN AND IT WILL SHUT DOWN IN THAT 2 SECOND CYCLE YOU ARE EXPERIENCING FOR SAFETY. CHECK THE PROJECTS FOR THE IDLE SPEED ADJUSTMENT. THIS IS WHAT WILL FIX THE PROBLEM. OVER TIME, THE IDLE SPEED GOES DOWN SLIGHTLY, AND CAUSES THE COMPRESSOR TO GO ON AND OFF. CLEANING THE IAC DIDN'T SOLVE IT FOR ME, ONLY THE IDLE SPEED ADJUSTMENT DID THE TRICK. HOPE THIS HELPS.

 

[Jeff Harwanko]

Great! Thanks TRTEX for the info! I'll be sure to print out that project and add it to my list for the weekend.