2006 fordf350 6.0 have an air conditioning problem. Runs good when idling goes in and out when driving down road.

 

If you use the search you will see that I asked this on Sunday (4 days ago) and nobody responded.

Through my own research I found that the likely suspect is a faulty high pressure switch that is located on the compressor.

Mine must have been a circuit breaker that reset itself, Sunday, grounded battery (oops) no ac above idle, Monday going home from work, normal ac.

 

David Martin, it's going completely in and out, or is it switching to the defroster only? That would just indicate a vacuum leak in the 4x4 system. I have this issue now.


Karl, you sure you don't have a small vacuum leak?

 

I had this problem about a year ago but it would also shut off completely sometimes. I had found that the actual *** for fan speed had worn out. The back of it is copper I think and after awhile that copped wears off. The person who owned my truck before me had tried to scrap it down or something with a knife. After buying a new *** it works like a dream. Pretty strong fan in these trucks!

The fan speed *** run from about $25 to $50. All depends on who you buy it from. O git mine from Ford for $45.

 

No vacuum leaks, blew out dash the whole time. I honestly believe it was an electrical surge. AC works fine, ground (+) cable twice, AC only at idle but ECT supports suspicion that AC clutch/compressor engaged, AC works as advertised on way home from work next day.

The focus here is (+) grounded twice.

Damn it, Jim! I'm a doctor not an electrician!

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David, could you define 'going in and out'? Does the airflow stay constant but temp changes? If so, I'd be looking at AC high pressure switch $35~$40 from OReilly's. I also found that a vacuum leak can close one door and allow hot (ambient) air in.

To check for a vacuum leak, remove glove box and watch how the shaft on that black box operates when the selector is moved (engine running IN THE DRIVEWAY). Then, have a passenger observe this area while driving/AC cycling from hot to cold. If the shaft doesn't move (from AC to vent) then you most likely have a bad high pressure AC switch.

Holy tumbling fat guys, Batman! I'm on a roll!!

 

Mine does that to but mine will stop cooling when at idle and then get cold again does not do this all the time. When it is working it will freez you out. Yet to figure it out

 

Eric, there is a low pressure switch in the tubing, I think by the condenser. That might be your issue.

 

I will check that today. I also ready about the clutch has a shim and sometimes you can take it out and that fixes it too.

 

Think i have found my problem was out looking at it today and when it stopped cooling i looked and the compressor was not on so i taped the clutch and it kicked on and started cooling so i am guessing its the clutch or that shim thing in it??

 

I am having a similar problem. I have a 2004 f250 diesel, and when I'm idling or at 30mph or less the air is ice cold and blowing great. But when I'm going highway speed or fast acceleration the cold air stops and it blows humid hot air. It's doing it while it's about 80-95 degrees outside. Any ideas?