E-body A/C control troubleshoot now Actuator Repair/Replace

Hey guys,

Not too long ago I rebuilt my A/C box as part of a larger project. Now everything is up and running and it blows ice cold.

Only problems is I think I swapped a couple of vac lines on the box.

When in the "Off" position, I get cowl air coming through the AC ducts like a vent
The "Max A/C" and "A/C" button functions are reversed - A/C setting blows recirc air and the reverse.
"Defrost" and "Heat" seem fine, but I haven't checked if they are pulling fresh or recirc air

I believe I just have the fresh air door vac lines swaped. I was careful to number them with tape and take pictures on disassembly, but I clearly didn't get something right on reassembly.

Anybody with knowledge of these things able to confirm my conclusion from troubleshooting? and/or point me in the right direction?

Thanks
Chris

Pretty sure the service manual has a diagram for all the vacuum line connections.

Did you have your 5 button pushbutton switch out? It's easy to put it in upside down. This would make the off position become defrost and blow through the upper vent.

Thanks for taking the time guys,



I took a look at the shop manual and the handy-dandy troubleshooting chart even lists my symptoms as fresh air door actuator lines reversed. Hopefully I can get at it without having to take the glove box out.



Not this time

I'll post back once I've swapped the fresh air door lines.

Couldn't be that simple....

When I was swapping the lines on the fresh air door actuator, I decided to run down the manifold vac supply line. The old (original) rubber line was sucking air while appearing intact. I replaced the feed line and now the fresh air door works as it should so A/C and MAX A/C function properly and the. Now the other doors aren't working and it blows out all the ducts at the same time.

Given it was functioning properly, time to check the controller vac connection and work to the actuators from there. Any other input appreciated.

Switch is basically its own internal vacuum leak at this point. Air comes out every duct in and under the dash at all times no matter what the setting. Testing it with a hand vac pump confirmed.

Used the hand vac pump to check all the actuators on the box from the plug. The fresh air door close actuator is a little slow and hisses, but everything functions as it should more than a year after my rebuild job, with just a hand pump, so pleased with that.

I ordered the OER repop switch, we'll see how it does. I like the OER paint, though I dispute the accuracy of some of their colors. Their fuel senders I had were both junk so I'm hoping the switch is not.

I'll close the loop here when I get the new part installed.

Ok, so switch and source check valve replaced. Everything worked great for a couple of days. Now the close side of the fresh air door actuator and the heat side of the heat/AC actuator aren't able to work at all without assistance. If you start manually actuating the doors, they will finish the job for you. The fresh air door was known to be iffy (hissing and took a long time to actuate) but the heat/ac actuator thing is new.

Anybody know how to fix these things or know of a vendor that sells or repairs them?

Also, is anyone with a parts catalog able to post p/n's for the ac box vacuum actuators? or direct me to where I can find the part numbers?

Thanks.

Seems to me I recall some vendor selling a kit to rebuild the guts inside one of the 5 button switches. New slices of bakelite/wax impregnated something-or-other with wedge-like slots cut out of them to direct the vacuum signal to the correct port depending if that button was pushed...remove the melted on tops of the pins, disassemble, remove old guts, install new, reattach top...

https://www.forabodiesonly.com/mopar/ams/how-to-rebuild-a-vacuum-heater-control-switch.58/

Thanks guys, I've got the old switch in my pile of parts to rebuild at some point. I've saved that doc. If summer wasn't bleeding away so quickly, I would have gone down that route right off.

In other news, my testing procedure (using a hand vac pump to test the actuators) was flawed and I bound up the linkage in the a/c door, probably by using way more suck than necessary to test. Anyway, after moving the rod by hand with the engine running, it started working again without any loss of vac. That one is good anyway.

I caped off the lines to the fresh air actuator and everything else works flawlessly now, but only in recirc for the moment. I'm thinking I've got to the end of the string of problems and know the fix.

Also, Original Air Group is locating either a good one or one they can rebuild for me and I'll send mine in as a core. I'm working on a way to get the china hat (or China sunvisor since it is just a circle and I don't know the term) off without having to unbolt the box from the firewall and dismantle my dash using a super long set of needle nose plyers and a lighted inspection mirror. We'll see on that front.

So I got my hands on a working fresh air door actuator and got it swapped in. I did have to unbolt the box from the firewall and the dash frame and remove the a/c ducting, but I was able to walk the retainer (China Visor?) off the end of the rod, and I have another part for the pile to try and rebuild somehow. I couldn't get a china visor back on the rod though, so zip tie to the rescue to keep the actuator rod from sliding off of the door lever. I also had to pull the heater/ac door assembly and flip the rod over to correct the linkage bind.

Anyhow, all working perfectly now and the Sanden/R134/parallel flow condenser upgrade has it colder, faster than the RV2/R12/serpentine setup it was born with. The re-sealed box with a non leaking switch and fresh air door actuator and my efforts to get tight air seals around all the ducting and vents has really made it work well. Great creature comfort upgrade.

The "sunvisor" ones are called push on shaft retainers, the "hat" ones are are called push on caps.

Just in case you ever need to ask for any at the hardware store.

Online source if needed.

Thanks Sniper, push on shaft retainer. That will save some time in the future.