We have a '73 200 I6 that I need to know about the vacuum lines. I have the entire dash dismantled now, fixing many different things. Got the dashpad recovered (not the best job, but my daughter's happy it's not puke green anymore! LOL) Replaced the headlight switch, and hooked up the wiper switch. Stupid dashlights still don't work. Rats. I got the blower motor working, but it doesn't switch from defrost to vents. I can see it's got a vacuum line from the bottom of the chamber, but the switch does nothing. All we have is defrost. Hope a diagram of where the lines go will help. Thanks - Rhonda
I am assuming your car is an AC car. Here is the diagrams to a 75 they should be fairly close http://www.maverickcomet.com/Repair/RepairInfo/1975VacuumDiagrams.pdf
vacuum diagram thanks. Yes, it does have ac, although I haven't even tried it, yet. I'm just going to track all the vacuum lines, first, then if they're all there, I guess the next step would be to figure out why it doesn't work. I'm very new to this, but so far with everyone's help, I've been able to track down all the problems. Actually drove the car up and down the drive (it's a long driveway) It goes, AND it stops. Rhonda
there should be 3 lines going through the firewall one of them goes to the vacuum canister (that is prone to leaking) the other line going into the vacuum canister comes from the carburetor. The other two lines go to a heater shut off valve on the heater hoses to the heater core. Make sure the vacuum canister is not leaking (it is a coffee can looking thing), you can test this by starting the motor and spraying the canister with carburetor cleaner(i have also used starting fluid in a pinch) if the engine rpm changes (either revvs up or stalls the motor a little bit depending on what you use) you have found your leak. Another thing that is prone to fail is the actual switch assembly itself. It is just common with these cars. After all the switches are 30+ year old peices of plastic.
I asked because it is a cable setup for some of the stuff on non AC cars but it is all vacuum on AC cars.
