AC/Heat vacuum leak?

[Lancer_Buck]

Hi, I'm having an issue with my truck's AC/heat system, and I haven't been able to find a satisfactory solution online, so I'm hoping someone here can help me out. I have a 2005 Explorer XLS, and the HVAC system only likes to stay on max-cold. When I bought it about four years ago, it had a clicking noise when I tried to switch it to heat. I used the guide on these forums to purchase and replace the blend door actuator myself for about 20% of the cost of what the shops were quoting me. This still didn't fix the issue completely, though.

I can get it to switch to max-heat only (nothing between max-cold and max-heat) if I put it on fan speed 2, 3, or 4 and flip the lever thing behind the glovebox (also found from these forums). If the blower turns off or goes to fan speed 1, though, the lever moves back into the max-cold position. This leads me to believe that it's a vacuum leak somewhere, but I can't find anything on where the vacuum lines are for the HVAC or how to check for/fix a leak. I don't really have spare cash or time, otherwise I'd have just taken it to a shop. Any help would be greatly appreciated.

 

[Lancer_Buck]

Still wanting to find an answer for this issue. I took it to a shop today, and they first told me that it was something with the blend door sticking and not being allowed to move into place. I reinforced the claim that I could move the blend door manually behind the dash, and that it would hold on all fan speeds except for Speed 1. They then told me it was an electrical issue with the blend door actuator, at which point I told them that I replaced THAT myself last year, and that you could hear the actuator switching over when changing the temperature dial.

They stood firm that it wasn't a vacuum leak, and wanted to charge me $700 to remove the dashboard to check it out, which is money and patience for BS that I don't have. If anyone could help me out with this, I'd really appreciate it. Having to manually switch it over, and only having the option of full-blast high heat, is a real pain.

 

[Number4]

Could be a defect in the manual control unit. With the three buttons. You could pick up a used unit for $20 and see if it starts working.

 

[Lancer_Buck]

Could be a defect in the manual control unit. With the three buttons. You could pick up a used unit for $20 and see if it starts working.

Which unit with three buttons are you referring to?

 

[Number4]

That be the one.