C3 68 air vent

[Rich G.]

My late 68 coupe owner's manual says,(page 29-30) regarding the "ball" vents; "shut off at the outlets is accomplished by rotating the ball outlet to the closed position. To difuse the flow,reach under the instrument panel and rotate the "L" shaped handle behind the outlets."

Problem 1. The left side is jammed and I don't want to break it. I have leaned on it as hard as I think is prudent. Any ideas on how to free it?

Problem 2. I can't find any "L" shaped handles. Were they deleted in later cars or is the book incorrect. This is a reprint owners manual.

Thanks

Rich Giannotti

[Chuck S.]

Re: C3 68 air vent

Rich, there's something strange going on with your reprint owner's manual.

There are about three different types of dash outlets discussed in the owner's manuals; I'm wondering if your quote is actually the instructions for the ball vents.

The ball vents have been around since at least the mid-sixties, and have always provided directed flow when the straight parallel louvers face outward and diffused flow when the ball is rotated (back to front) into the reversed position.

Starting in 69, Corvettes with C60 have push-pull knobs at the ball vents to shut off the air flow. I am not sure how the flow was shut off in 68; maybe an "L-shaped" lever under the duct?

If the ball will not rotate in the outlet, you will probably have to remove the outlet from the dash and disassemble to find the problem. It may have dirt/debris jamming the ball. There are some felt strips that seal between the ball and the outlet to prevent air leakage...there should be nothing to prevent the ball from moving.

[kelly theaker]

Re: C3 68 air vent

i believe the door lock push pull for the ball vent on the dash pads was present for both air and non air . the problem he may be having is the shutoff is a riveted steel mech behind the ball , for lack of the correct terminology and with a leaking windshield , he may have a rust buid-up, just a thought and i may be wrong on the a/c only , my E 69 has but i have not owned since new , and Chuck you sound Knowledgable and may have restored or viewed many examples .

[Chuck S.]

Re: C3 68 air vent

You're right Kelly, both air and non-air cars in later years have shut-off valves. For non-air cars, the dash side vents and kick panel vents provide outside air for ventilation, and the ball vent shut-off valves can be used to regulate the air at dash level. I started to correct the omission, but decided against it since that seems to cause problems if someone responds quickly.

I thought Rich was saying he couldn't rotate the left vent ball. On his 68, which does not have the push/pull buttons, I thought he was saying he couldn't find any shut off valves. Rust is a possible cause of the problem, but he won't know until he takes the outlet apart.

I profess DETAILED knowledge about only one 70 Corvette. Some of that knowledge can be applied generally, and some of it is useful only for very late 70s. In my enthusiasm to help people, I sometimes forget that my knowledge may be absolutely useless for the year in question.

[kelly theaker]

Re: C3 68 air vent

I certainly appreciate the responsessssss, and need the assistance and Knowledge base of members like yourself, considerate and keen to help.

[Roberto L.]

Re: C3 68 air vent

In my 70, non air car, those pullers were sized/rusted and I had to dissasemble them, repair the broken plastic parts and replace the seals in the inner ball doors. They have two stops and the chrome puller handle is screwed in, the same piece which is found in other GM cars for different applications (ie door locks)

Roberto, NCRS #30019, RMC