just bought a 77 k5 and air slowlyblows out tha ac and heater vents even with tha blower switch off and when islide the control to max on tha ac it blows wide open. is it the switch ? can i bypassthe switch and use a toggle switch to operate the fan motor just for the heat?

 

The fan never shuts off on these trucks. You could wire in a cut off switch if you like.