I got the AC charged up on the vette today, and i guess i did a decent job on all the o rings and fittings etc, because there are no leaks. They said i have 2 issues. i need to seal the front condensor better with foam top bottom and sides. also my controls dont function correctly? I installed a new control; assembly, but the AC blows on the floor and not out of the vents. What is the fix for this? When you go to floor defrost or vent those work fine.

 

I suppose "new control; assembly" included a new vac. switch in console.
Check the A/C Vent Heat vacuum source- a small black plastic tube that goes in below the hood alarm switch, pass. side of dist. into wiper valley.
There are typically several vac. connections at the intake source. A hose can be split at the connection. Even if all are connected good the A/C Vent Heat black plastic tube vac. line from engine is typically fragile from heat so it may be cracked- replacing most of engine side w/ hose will fix.


I wrote this up awhile back for this problem.
On at least later C3 the problem is that heater is the default position (no vac. or vac. leak) due to being designed in the north. Vent should be default. Very safe bet the problem is 1 OR 2:
1) The vac. line from engine may be damaged from heat - a small black plastic tube that goes in below the hood alarm switch into wiper valley. Replacing most of engine side w/ hose will fix. OR
2) The vac. switch itself is not switching due to vac. leak as the usually plastic rivet is not holding the 2 main switch parts together well. Besides replacing, it is also possible to tighten this &/or lube w/ a thin layer of white lithium grease to fix.
3) If you have a heater, the small vac. tube to heater hose valve underhood may be damaged from heat & need replacing. Block w/o heater.

PS The design problem comment is not intended to be offensive to any of our northern friends.

 

All the engine compartment hoses look to be solid. i pulled off what i could, and sucked on them. i almost passed out. lolol. Will have to pull interior out of car to look at the rest now.

 

Purchase the AIM. It has a diagram showing all the factory AC vac hoses, colors, connections, where they go, what doors open when, etc.

 

I got the aim manual from Wilcox, but it is such a bootleg copy that you cant read half of it, pretty sad actually. I was wrong, the vent doesnt function at all. as i said i will have to rip the interior out to get this sorted out .

 

What year? I might have a clearer AIM page.

 

Its a 1980, thanks for the help.

 

Mine does the same thing I guess I'll keep my eye on this post

 

 

Just throwing this out there.....

On my white79 I accidently tugged on the "main" small black tube that connects to the larger vacuum lines near the brake booster.
Came out of the firewall Thought I'd need to get under the dash to run a new one but it turns out all 3 small tubes that go through the firewall have vinyl connectors at the grommit. Just needed to plug it back in. Don't know if it had been disconnected for any amount of time of if I had actually yanked it out.

Just something I learned on these C3s after 30 years

 

well i cant read that diagram its too small for me.lol. Where can you get the correct type of hose for this system, i might as well replace it all. what size is it?

 

You are on the right track, check for vacuum from engine. The tube could be kinked from interior work. Pull up pass. ft. carpet, then pass. console side off. If vacuum at switch press the 2 switch parts together.

 

It's not a boot leg copy.. it's the only thing out there...

But.. go to my site... you'll find what you need..

 

All these pictures are now listed in the new section.... "Tech pictures"



need more let me know..

Willcox

 

Sorry Bootleg is such a strong word. it just seems that the manual was scanned and saved as a pdf then put on a disk. The first half of mine is very blurry and hard to read.

Thank you for the printed copy.

 

Will call you tomorrow about ordering a hose kit as well.

 

Not a problem Grumpy.. the books I used were actually much older books than the current printed versions offer and the pictures in most cases are better... Some go back to the early 80's and the one used on the 62 book was one we have had since the late 70's.. I did the best I could with what I had.... and chose the older better quality books vs. the newer ones.

Some books are better than others.. In most cases if you have a blurry picture.. just message me and I may have one from a different book that will help clear it up for you. But given what we had to work with the pdf books actually turned out pretty good.

The pdf's afford you the zoom option.. (for people like me that can't see this is a must) and they have key text words embedded in them that help with the search function. But the good thing is that the pictures are better than any printed versions by far.

 

Hose kit ordered, will pull passenger side apart once its here and sort this out.

 

I've worked on a 78 fairly recently that had a vac problem too, turned out that the grommet at the firewall was a vac line connector too, the vac line inside had pulled out of the grommet.. easy fix if you can fish out the inside vac line to the engine side of the firewall. Worth a check before pulling the dash apart.

 

I guess I don't understand how to interpret the troubleshooting table from the pictures above. Shouldn't I be able to hook a vacuum pump to port 1 (where the source vacuum comes from), move the control lever to DFR, apply vacuum, and open the defroster door? The problem is that I bought a new control switch (not the entire head), hooked my vacuum pump to port 1, and I'm not getting any doors to move or anything when I move the control lever from Off through DFR. Am I doing this completely wrong? Any help would be appreciated. Thanks