Alexstone0429

Got an 89 camaro with an engine swapped 350 from 305, T5 manual.
In Australia so car as been swapped to right hand drive and previous owner fried ecu. So has a sniper 2 EFI on it.
Just wondering what vaccum lines needed to get ac to work.
Currently the air comes out the defroster. Just want to be able to change it to face air vent. I have two vaccum lines I can find coming out of the wiring loom that comes out of the firewall near the driver's side (original passenger side.) currently the longer one is capped and the shorter one is just open.
Also to note the original vaccum bowl and cruise control was removed.
Any help is much appreciated thanks.

punkmaster98

iTrader: (5)

one line needs to be connected to the vacuum source. the other line goes to the heater core bypass valve. once that is corrected you will need to see if the vacuum selector switch hasnt failed.

sofakingdom

iTrader: (1)

Those 2 lines should be different colors; one purple, one grey. The purple one goes to the source of vacuum, which would be a convenient nipple on the intake somewhere. Vacuum should be routed from the source, to a check valve, to a reservoir, then to the line going through the firewall. The check valve should be oriented so that vacuum can go from the manifold toward the car but not the other way (you should be able to blow through it from the car toward the intake but not the other way). The reservoir is needed to store enough vacuum so that when engine vacuum goes away (hard acceleration for example) it contains enough to keep the air routing doors in their chosen positions, and not return to their "rest" state. If your reservoir has been removed then you need to get one off of a junk car; doesn't particularly have to be a Camaro, or an 89, or even a GM car for that matter. The grey line goes to the heater control valve.

wilmil

Sorry to hijack this thread, just didn't want to start a new one to the others. I have an '83 'bird, and air comes out only through defrost. I have taken apart most of the dash, and looking at the HVAC module, it looks like all the vacuum lines are ok. At least the colors match to the rubbery vacuum connector that collects them all.
I then look in the engine compartment and there is a black broken plastic hard line and a vacuum storage on the drivers side firewall. It has a vacuum hose connected to the bottom connector from a tee on the intake. The upper one does not.
I went to NAPA got some vacuum hose and a universal check valve. Connected hose to broken plastic line ran to check valve, then to upper connector on vacuum canister on firewall.
Got in car, turned on key and turned on vent and fan. Still coming out defrost vent. Flipped vacuum check valve, still same result.
Took apart vacuum dial on back of HVAC module. Disc looks intact. Out of ideas Any help?

Will

sofakingdom

iTrader: (1)

For troubleshooting purposes, you can hook up the vacuum lines one step at a time. Like, run hard engine vacuum (no check valve or reservoir) to the control head, and see if it works. If it does, then you know the CH, vac motors, etc. are good; if not, you do the math. Then add the check valve. Yes/no? Then add the reservoir. Not too hard to figure out if you just apply some logic.