65 Riv AC blower control issue...

[Guest Im4darush]

On my 65 riv with A/C I get nothing coming out of the vents when I turn on the air conditioner. I can hear the blower motor turn on, but no air from the vents. The AC compressor turns on. When I turn the heater on, then I get air from the dash vents.

I assume since the controls are separate for the heater and AC, air should be coming from the dash vents without turning on the heat?

I have manifold vacuum at the canister on the passenger fender with one vac line connected to it. I also have two vacuum lines that have been plugged by the PO that are just affixed next to the vac canister. If anyone has a diagram of where these vac lines should be connected, or if someone could just let me know, I would really appreciate it.

The vacuum canister only has 2 nipples on it. One for manifold vac, and one other, though I do see another hole next to it so I am not sure if a second nipple has broken off.

Any info you could offer would be great.

[RivNut]

There's another diaphram that's under the heater box. Tought to get to.

Ed

[Crazy4cruz]

Here is a diagram of the vacuum lines that might help. I have the exact same issue so if it turns out to be the second diaphram under the heater box let us know. And RivNut is right. The one underneath is a bit "tough" to get to.

[Seafoam65]

Here is a diagram of the vacuum lines that might help. I have the exact same issue so if it turns out to be the second diaphram under the heater box let us know. And RivNut is right. The one underneath is a bit "tough" to get to.

[ATTACH=CONFIG]272684[/ATTACH]

What makes all this lots of fun is if your car is like mine, all the colored stripes on the hoses have

worn off and you are looking at black spaghetti. When I bought my car, several hoses had split on the end and fallen off but they were close enough to where they were plugged in that I was able to guess where they went and guessed right. All it takes is for one hose to fall off on any of the hoses and it will blow out the defrost on A/C.

[Guest Im4darush]

What makes this even more fun on my car is that my car's heater core is bypassed. Here in FL we don't want any heat coming close to the cabin especially when the AC is on. And in addition to that, my car has the throttling valve update kit on the AC so trying to figure out where these hoses should go NOW is fun to say the least.

I had a few lose hoses laying around and hooked up each one to the vacuum canister. One of them sends air through the vents when I turn the AC on. This is a step in the right direction as AC is what we need around here. Issue is when I put the lever to recirculate, I get nothing out of the vents and hear a hissing behind the AC controls. So its sucking air back there.

Where is the 'outside/recirculated' diaphragm located in the car? Is it the one mounted just behind the passenger valve cover? I can feel the diaphragm that is under the blower but cant feel any vac hose nipples on it anywhere.

[Eric's.64.Superwildcat]

Rush,

Do you have the chassis manual? It will show the position and routing of all heater/AC components.

You're better off troubleshooting A/C issues (i.e. blowing cold air) separately from air flow issues since they are largely independent of one another. You are correct that the "outside/recirculated" vacuum is mounted below the blower. It is a two-stage diaphragm and should have two lines going to it.

If you can hear a vacuum leak behind your heater and A/C controls you should start there since it is closer to the vacuum source - if you're losing vacuum there then you'll never get it down stream. The vacuum lines are color coded and each color's function is documented in the chassis manual.

Vacuum is only one part of the puzzle, the other part is the actual functioning of the mechanical doors within the ductwork. For example, when I removed my "outside/recirculated" duct I found a broken spring and the vent door was just hanging there. No amount of vacuum line work was going to fix that. There is another vacuum controlled door for temp control (also with a spring attached) and then there is door for redirecting air to the front windshield defroster - which is cable operated.

I've included a couple of photos below so you can see what I'm talking about.

Please keep this thread updated with your progress and good luck.