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I am not able to keep the temperature lever at full cold. The other end of the cable is attached to the intake flap but also butts against the coolant vacuum switch. What that switch does is when the temperature lever is positioned at full cold, the switch closes providing the vacuum needed to close the coolant valve in the engine compartment preventing coolant from flowing into the heater core. However, this vacuum switch has a spring at the end that helps it turn off the vacuum to the coolant valve once the temperature moves away from full cold. The problem that I have is, no matter what adjustments I do with the temperature cable, the cable does not have enough friction to stay put and the spring at the end of the vacuum switch pushes the cable away opening the coolant valve.
Has anyone else ran into this problem and if so how did you resolve it? With summer right around the corner, optimizing A/C temperature and air delivery is essential!
Years ago I had this same problem with a replacement switch on my 77. This is what I did to correct the problem. Now you may have to go to a hardware store and just get a little lighter spring.
Years ago I had this same problem with a replacement switch on my 77. This is what I did to correct the problem. Now you may have to go to a hardware store and just get a little lighter spring.
Nice! I may have to do just that! I don't suppose these switches are available for purchase out there?
In the interim, being you are in Texas and the heat is probably getting up there, disconnect the two vacuum hoses leading to and from the switch and connect them. You will have effectively bypassed the switch and will be in constant a/c mode until you can get a replacement switch. The new USA switches are the way to go, correct spring and all. The imports are JUNK.
In the interim, being you are in Texas and the heat is probably getting up there, disconnect the two vacuum hoses leading to and from the switch and connect them. You will have effectively bypassed the switch and will be in constant a/c mode until you can get a replacement switch. The new USA switches are the way to go, correct spring and all. The imports are JUNK.[/QUOTE]
Dave, that's a great idea but it looks like the original molded switch connector is still intact. The OD line size of the switch connector is not a common size to just make a loop between the black and white vacuum lines, any suggestions as to what size line to get for the loop?
I removed the old switch and it looks like bubba has worked on it good - need to get another one! Wilcox is not on my preferred vendor list due to an unresolved dispute but that is another story. I looked at Corvette America and did not see anything. Anyway, for now, I looked through my vacuum parts pin and was able to hook the two lines together and the heater valve is now shut off. I had to replace the white hard line that went from the switch to the engine bay. It was brittle and cracked. It was a 1/16" vacuum hard line.
79 - Coolant vacuum switch
