Cutlass Gurus, I need your help!

[DiscoStudd]

My 'rents are having issues with their Cutty's climate control. First off, it's a 92 Cutty Convert, 3.1/4T60 with the "digital" climate control unit (it has steering wheel controls for the CC, if it matters.) Last week when I was visiting them, my stepdad told me of how the "vents" always stay on Defrost no matter what mode they select. He said that his buddy had just replaced the vacuum check valve not too long ago. I took a closer look and found that his buddy didn't replace the check valve with the correct "3-Way" valve, and left the line running from the manifold disconnected. I temporarily disconnected the line to the cruise servo and connected the line from the manifold there and all seemed to be well again. Or so I thought. Couple of days later, he tells me that the airflow was weak out the vents and mainly blew out the floor when it was in "UPPER" mode (which should be vents only.)

 

I took a quick peek at my Regal's setup (of course I don't have a vacuum cruise servo, but everything else was the same) and went and bought the proper parts, including the 3-Way check valve and the nipples to properly connect the plastic tubing to the rubber lines. So I went over to their house tonight and hooked everything up the way it's supposed to be, and it's still doing the same thing ("Bi-Level" style actuation when it's in "UPPER" mode.) I felt up under the fender and found the vac canister and the line is connected properly.

 

So now my question: Is it possible that something is broken up under the dash (like a vacuum line)? Or is this a problem with the control unit. The unit does seem to function properly in all of the other modes (the fan seems kinda weak, but that could be from a plugged up evap core.)

 

Any suggestions from the experts would be greatly appreciated.

Thanks!

[DiscoStudd]

Thanks for the advice, Dave! Any pointers or shortcuts to getting that dash apart quicker? Would I have to remove the dashpad to gain access to the dampers?

 

Thanks again...

[NOHC_WBody]

Any pointers or shortcuts to getting that dash apart quicker?

 

[DiscoStudd]

I was thinking about using this:

 

 

[NOHC_WBody]

You gotta think..that chainsaw's gonna sling a lot of oil around..you gotta clean all that up.

[slick]

Check all the lines under the hood as well, besides for the 3 way valve. One of mine will intermitantly disconnect itself right behind the top of the engine. I know right where to look everytime as well.