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I'm in the process of resurrecting my 1968 coupe, just now starting the vacuum system. The vacuum diagram for the wiper door shows one input and one output on the vacuum control solenoid that is mounted on the back of the tach. Looking into replacement part for GM 5638276 i noticed that some have two outputs and some have one output. I don't know that mine is defective and i haven't dismantled enough of the dash to see what i have, just looking for the best option to replace if I need to. Any wisdom out there would be appreciated.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
this is what you should have and the hose routing.....the actuator relay valve will go bad for no reason. Usually the orings leak. The one for the wiper door in in the passenger fender behind the expansion tank just above the wiper reservoir...pain in the *** to change. Its the same as the headlight door actuator relay...its got the 4 hoses going to it. THe valve on the tack is actually a vent....its closed to close the door and open to open the door so it fails open. So the red hose is closed and the blue hose is open
Last edited by Rescue Rogers; Mar 22, 2025 at 08:00 AM.
68 vacuum system
