Aloha hurst ohana. Question. It's been a while but I have a question. My ac is cool but the air isn't blowing through the vents properly. Its blowing more from the bottom than the vents. I had this issue 40 Yeats ago and I forgot how to fix it. Was it the black ball in the engine bay or inside the dash, the vents are stuck. Any help would be greatly greatly appreciated.
thank you very much in advance

 

Start with confirming vacuum to the black ball canister, both hoses are attached and that it doesn't leak.

 

Common problem on G bodies: there's a plastic rivet/push pin that holds the vacuum selector disc together in the heater control that dry rots and fails. Disassemble, clean, lubricate, and replace the failed fastener. I believe I used a truss head self tapping screw, but there are other methods aa well.

 

Thanks for this Flemming442, I've got this same issue in my 1979 H/O. Will check it.

 

Buying an NOS 9 port switch would scare you right about now.

Best to see if you can fix what you can.

Do not rule out the possibility of the vacuum pods themselves. If they go out, you may not be directing air to where you want it.

Here's the back of your head unit. You can see the round 9-port switch on the left in the picture here (will be on passenger side when looking from the front). Held on with screws. While your in there, inspect the vacuum tubes for wear/holes/cracks, etc.



This is from a later Olds G-body CSM, but essentially it's the same stuff.

 

thank you everyone for your help.

 

Ditto for me, thanks, I just got my 79 H/O back out of storage and I have got to get this fixed before the show the end of this month.

 

Come to think of it, I replaced all 3 switches with NOS ones when I replaced the faceplate, I'll look to replacing that black ball and go from there.

Thank you Jusrushem for starting this thread, your timing was impeccable.

 

By Vacuum Pods, did you mean the Actuators? Also, I'm noting the A/C Max isn't working a well, I'm hoping a new black ball will revolve all this.

 

Yes, pods means actuators. However, before spending money on a new vacuum ball, do a vacuum check on it. It's simply a vacuum reservoir tank, nothing more. Plug one side, pull a vacuum on the other tube, see if it holds. If it does, don't waste money on a new tank. To this day, I've never heard of a vacuum ball failure, but that doesn't mean it doesn't happen. There may also be a vacuum check valve in the line going from manifold vacuum to the tank, but not always. The lines are also a problem area for vacuum leaks, especially those around the engine. So be sure to check for brittle/cracked lines as well.

 

Will do, thanks. I've got an NOS vacuum reservoir (somewhere) so if it's that I'm set as long as I can find it. Mine's got no check valve in the line so I'm good there. This issue existed prior to my putting in the HVAC control unit with all the new switches on it, so I think I can rule the unit out as being problematic. Perhaps a loose or disconnected vacuum line but I think I probably would hear that.

The A/C works great but it's only coming out the bottom and for the heat predicted at the show next weekend, it's not going to cut it. The cabin cools down way too slowly and there may be 4 people in the car so that ain't going to go too over too well. If I can't get it fixed in time I will have to take another 79, probably the black/silver brougham.

 

IIRC, the bottom one is a "neutral" actuator. Meaning it needs a vacuum signal on one side or the other for it to move the bottom door. That door directs it to the floor, floor and vents (bi-level), or just the vents. It's not spring loaded. Upper actuator operates the defrost or vent mode.

 

Thanks and I'll give this a try this weekend.

 

Great knowledge. Thanks for that. Vacuum lines can really be a hassle. I passed on a fully loaded 60 Cadillac once seeing all those vacuum lines going into the driver's door. I can do electrical all day. Vacuum lines?

 

Another big THANKS to Jusrushem for starting this thread, and to all who added in some insight to this issue, especially 69HO43 for providing the photo and the diagram.

Problem solved. It was the plastic push pin in my NOS rotary vacuum selector switch. Not only was it broken, it was gone and the wheel piece was just hanging there. I believe this was done in my me when I first installed the unit and (due to a loose bolt getting stuck underneath it) I was too aggressive with the slide selector and I broke it, not knowing what I did. I had a spare push pin from another unit which is old as well so down the road it will need to be replaced when it too breaks.

For anyone doing this job I highly recommend getting the 1979 manual and using the troubleshooting diagram on page 1B4-4 CUTLASS AIR CONDITINING. Follow it and you will succeed in getting the job done. I used a jumper hose instead of a vacuum pump for testing the hose lines, but either/or will do it.

Thanks to the help from all of you, I can now take my 79 H/O to the Georgia Moonshine Cruise the end of this month and I will not have a sweltering wife and 2 sweltering guests (one of whom will be the 79 H/O advisor for the H/OCA) in the car for the show.

Much appreciated!

 

Glad I could be of assistance 👍👍

 

Nah. I don't deserve any credit. I want my 83 running like a champ. But I'm glad someone's tip helped you. I'm still stuck. I haven't tried that yet. Starting off on the easy route 1st. Now for the harder part.
thanks again everyone for all your help.