Climate control problems

[All around mj]

So about 6 months ago I noticed my climate control can be switched to all positions but it is stuck in defrost. I’ve messed with some of the vacuum lines and found a one way valve was stuck shut on the intake manifold so I freed it up. Has anybody else run into this issue?

[All around mj]

Oh yeah, I’ll also add, the one way valve didn’t fix the problem.

[Ωhm]

18 minutes ago, All around mj said:

I’ve messed with some of the vacuum lines and found a one way valve was stuck shut on the intake manifold so I freed it up.

 

How did your actually fix this?

 

Also, lost of source vacuum causes the ventilation system to default to defrost only.

[All around mj]

I haven’t fixed it. I was just reaching out to see if anyone has run into the problem and what there solution was.

[All around mj]

I may just have to take the dash back out and check all of the vacuum lines. I’ll have to try it out Thursday after the kids go back to school.

[cruiser54]

Begin at the vacuum reservoir behind the passenger side front bumper and work toward the firewall. 

[All around mj]

48 minutes ago, cruiser54 said:

 

Begin at the vacuum reservoir behind the passenger side front bumper and work toward the firewall.

 

Thanks if I get to leave work early today I’ll get started on that.

[gogmorgo]

Common place for the line to the reservoir to get damaged is where it runs past the battery. It's pretty easy to catch it with the battery while you're changing it. I've also seen pretty poor jobs of sealing the vacuum line to the heater valve after it was deleted. 

[All around mj]

4 minutes ago, gogmorgo said:

Common place for the line to the reservoir to get damaged is where it runs past the battery. It's pretty easy to catch it with the battery while you're changing it.

Come to think of it, I may have changed the battery around the time the problem started. Thanks for the input. I will check into it on my lunch break.

[All around mj]

I did kind of a quick visual/feel check by the battery but nothing too in depth. Since the cruise control ties into the line just behind there I’ll see if it works on the way home. I can take the battery out and do a better check after I get home. If I don’t find any issues under the hood I will assume I could have a rodent problem or maybe a bad seal/line behind the dash.

[All around mj]

Well the cruise control worked fine and I didn’t see any problems under the hood so I guess that means I’ll be taking the dash out. I’m probably going to wait until I redo my a/c. Neither of the systems were charged when I got the Comanche nor the donor Cherokee.