usually the original shut off was located between the heater core and the engine block. it kinda looks like a crooked letter "P" with one hose going in and another going out, with a small vacuum line somewhere in the middle.... was not one of GM's best designs, and typically they stopped working and were usually taken off or replaced with a gate valve of some sorts... or some of us would just disconnect the hose all together and route it back to itself on the core, and the other hose from the pump to the intake..... of course when colder weather comes around, would have to route them properly to get a little heat inside...
here is a picture of the control valve...hopefully,
StingrayJim NCM Lifetime Member #1936
Stingray's '76 StingrayJr's '78 Lil Red '94 (click each one to see a bigger version)
Corvette is a registered trademark of the General Motors Corporation(GM) &
Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise
noted) and does not claim or imply that Chevrolet or
GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated
with, sponsored or supported by GM. Copyright/trademark/sales mark
infringements are not intended, or implied and are in fact used to support
GM, Chevrolet and Corvette.
Official C3 Vette Registry content is Copyright 2001-2018, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS
Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982