AC stuck on defrost

[lonestarjeff]

My 2000 XLT suddenly wouldn't divert air to any choice but defrost last week. I'm always amazed when my mind skips over the most simple explanation & wants to make things more complicated. I spent several days researching the ways to repair or replace the front unit blend door or door actuator(which is pretty much a PIA project any way you go about it). Almost ordered a new actuator, but something made me hold off a little longer(I guess something is still working properly in the dark recesses of my mind somewhere).

Thankfully, I had a logical thought before falling asleep a couple of nights ago & realized the blend door has nothing to do with which holes the air comes out of. Next morning I found the crumbling vacuum hose fitting next to the firewall above the ECM housing. Nice cool air is now blowing out of the dash vents again.

P.S. The blend door in my rear unit IS getting a bit cantankerous this past year, but still working so far.

Jeff

 

[hammerg26]

Picture?
Have the same issue.


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[lonestarjeff]

That's from my F150, but Expedition looks the same.

 

[lonestarjeff]

Yours may have another T with a rubber cap. I think it's a test port, but any of the old soft parts could be leaking enough to cause the actuator under the dash to fail.

 

[hammerg26]

Thank you, sir.


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[William1]

Definitely as lonestarjeff stated, be sure to look at your vacuum check valve. Also, take a really close look at the small tubing leading to and from the valve. I had this same issue in my 01 Expo 4. XLT. I replaced the check valve with no result. But I missed a pin-sized hole in one of those little vacuum lines the first time around. Once I found the hole, I cut the tube and fed either end into slightly larger tubing and sure as hell, I have A/C flowing through the front vents again!

Be advised, there could be dry rot or a hole in the same hose leading through the firewall to the climate control unit...

Best of luck!

 

[hammerg26]

All fixed. Bought 18” of vacuum hose and replaced almost all of the vacuum lines on that system. Check valve was good. But there was a ton of dry rot. Truck is 20 years old - it’s expected.

Thanks for the help.


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[juan214]

While your at get some 3/8" fuel line as back up. The vaccum lines from the back of and the left of (looking at engine) of the intake to the PVC spliter are hard plastic and break when they get dried out (or when its freezing out) and get brittle. The fuel line is a quick fix.

The engine will stumble when either break.

 

[Eileen]

I'm piggybacking on this...I have the same issue, and I have identified cracked and just plain old vacuum lines as the problem. They are cracked at the control valve on two sides. And one is cracked a little farther down the line. I cannot physically reach the ond of this connection, so I need a coupler I guess. Someone mentioned 3/8" fuel line. Mine are not 3/8". I just want to purchase some tubing that can be used to replaced my cracked bits, with a coupler of sorts. I have an 03 expy and the tubing looks like 1/8" or maybe 3/16". I'm totally fine with a tiny fuel line...I'm ready to use an icemaker line at this point - but I won't! Can anyone offer information on the actual parts to purchase so I don't sound like an idiot when I go to the parts counter?

 

[Eileen]

I found this: https://www.partsgeek.com/spn7ysd-ford-expedition-ac-vacuum-hose.html