Had the AC fixed...but

Reply Subscribe

Thread Tools

Search this Thread

Jun 19, 2008 | 08:31 PM

ag-ford-4x4

Thread Starter

Fleet Mechanic

Joined: Aug 2005

Posts: 1,689

Likes: 29

Had the AC fixed...but

So i got my AC worked on, and i THINK its working right. I can get it to 45 or so on a 99+ degree day. Here is my question though. When its say 80 degrees outside, and the AC is set on vent or outside air, if i am sitting still, the AC vent temp will only get to about 70. Is this normal? I know the heater core bypass is not engaged on this setting, but shouldnt the system perform better than that sitting still? Is that just a crappy design flaw for these trucks or what? Its a 2005 SD Diesel.

Jun 21, 2008 | 06:26 PM

Old Ford Blue

Senior User

Joined: Dec 2007

Posts: 206

Likes: 0

From: Good Hope, GA

If its on vent its only sucking in outside air and shouldn't be cooling it at all. What does it do on normal AC(AC sucks in outside air and ACs it, max sucks in already cooler in-cab air and cools it more).

Gabe

Jun 22, 2008 | 04:43 PM

BillC

Elder User

Joined: Jul 2003

Posts: 531

Likes: 0

From: North Richland Hills, TX

It's because you're sitting still. You're not getting the heat transfer across the condensor. Does it work ok after you start moving?

Jun 23, 2008 | 12:29 AM

Bern_F150_4x4

Elder User

Joined: Apr 2003

Posts: 673

Likes: 0

From: Maryland

If the problem only happens while sittting in traffic, check your fan clutch. Is your fan shroud still in there?

Jun 23, 2008 | 12:26 PM

ag-ford-4x4

Thread Starter

Fleet Mechanic

Joined: Aug 2005

Posts: 1,689

Likes: 29

It cools great when you are moving. I can get vent temps down to 42 with 99* ambient temps. Its just when sitting still and on outside air that is warms up a LOT. The fan is electronic as far as i know.

Jun 23, 2008 | 07:04 PM

Bern_F150_4x4

Elder User

Joined: Apr 2003

Posts: 673

Likes: 0

From: Maryland

I would still focus my troubleshooting on the fan. A simple test would be to open the hood, cold start the truck and turn the A/C on; the electric fan should come on immeadiately to move air over the condenser even though the engine is still cold. What you describe is an air flow issue with the condenser. Is the truck running hot in traffic? See if you can round up a shop manual and try to confirm the fan operates as it should. could just be a bad relay...