1967 ac controll hiss

carbuff67rs · Mar 27, 2015

Ive got a 1967 RS 327 with factory ac. When the motor is running, Ive got this hissing sound coming from the area of the ac controls in the dash. When I shut it down the hiss lasts for about 4 seconds until the vacuum from the canister is all spent. The controls all seem to work though. I can hear the vacuum operated door in the ps kick panel open and shut when I switch the top lever from side to side. Is there supposed to be a hiss or do I have something leaking? Ive seen the website for the guy that rebuilds the controls and sells the master vacuum switches so I kinda know whats in there. My ac is disconnected under the hood.(compressor removed) so I dont need ac but I would like all the little doors and vents to open and close like they should. Will it still work as a heater if I just plug the vacuum line under the hood?

john68 · Mar 27, 2015

You do have a service manual, don't you, there is a vacuum switch for compressor.

carbuff67rs · Mar 28, 2015

There is? There was just a 2 wire electrical plug on the compressor with a blue wire and a ground. Is there a second vacuum switch under the dash that activates the compressor (blue wire) by sensing vacuum from the one on the main controls? I will have to check my aim then. That would explain why the blend doors all work fine still.

carbuff67rs · Mar 28, 2015

So, there is a second vac switch just for the compressor. And it was a dark green wire and not blue as I first thought. I will have to look into this more on sunday

jerry67 · Mar 28, 2015

You may find the following thread useful, although it pertains to a 67 firebird, it is the same as Camaros except for compressor mounting, hose routing, and location of the drier, and maybe some other under the hood components I'm not seeing ,but the system is virtually the same, especially the under dash components which starts on page 3. The poster does a great job explaining everything in detail and pictures.
http://firstgenfirebird.org/forums/ubbthreads.php?ubb=showflat&Number=208025&page=1

carbuff67rs · Mar 29, 2015

jerry67 said:
You may find the following thread useful, although it pertains to a 67 firebird, it is the same as Camaros except for compressor mounting, hose routing, and location of the drier, and maybe some other under the hood components I'm not seeing ,but the system is virtually the same, especially the under dash components which starts on page 3. The poster does a great job explaining everything in detail and pictures.
http://firstgenfirebird.org/forums/ubbthreads.php?ubb=showflat&Number=208025&page=1

Thanks, that link was very helpful. The aim is good but sometimes an actual picture is more helpful.

john68 · Mar 28, 2015

someone had picture of the vacuum switch within 2 weeks here

1967 ac controll hiss

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