Beta Vacumn Actuators

[davidb]

What's that thing on the firewall above the P.S. rack? Are they
prone to frying? Is there another vacumn heater actuator buried
WAYYYYY ahead of the shift lever, center? Like Scorpions? My
cowl flap won't open. Trying to get the HVAC system working.
Thanks.

[Jim Fierst]

That vacuum motor is for the heater valve and allows the water to flow to the heater core when open. A separate motor uses the same vacuum line to open the door and it is located up inside the dash. If you are going to get involved with the heating and cooling vacuum moters I would suggest you get a copy of "The Air Conditioning System Helper " a 1979 document which is a color graphic which shows all the lines ,vacuum motors etc. for heating and cooling and all the door positions. Also get a vacuum pump and start at the vacuum chamber and check to see that it holds vacuum. The pump will come in handy checking out the individual motor functions. I plugged it into the line from the vacuum chamber to check out the entire system for leaks and then individual switch functions.

[davidb]

Thanks Jim F. 4 all suggestions. Hoping Keller will kick in
advise too. Will H. sent me copies of his HVAC revised/
labeled Scorpion system which was invaluable as my PO
had disconnected most everything. Hopefully I'll sort out
my Zags HVAC problems w/o resorting to my normal routine:
checkbook mechanic.

[SubGothius]

The VERY first thing to check is the main vacuum line to the whole HVAC system; this can often disintegrate and/or collapse particularly where it runs across the firewall above the exhaust, or one end or another may be cracked.

My HVAC had never worked since I got the car. I was fiddling with my vacuum connections one day, found the manifold end of my HVAC hose was hard and cracked, so I sliced off about 1/2" and reconnected, and voila, working airflow control!

If the ends are all fine, it may be worthwhile to try just splicing in a new section across the firewall span, or just replace the whole line from manifold to the HVAC box inside the car for good measure and peace of mind.

There should be a line from your manifold to a vacuum accumulator cannister, then another lonnnnng line from that to the main HVAC box inside the car. I don't know where that vacuum accumulator is located on an FI car, but on my '79 with the same dash/HVAC system, it's a plastic cannister on the driver's side fender just behind the headlights.

[Jim Keller]

I have found the vac lines in the engine bay go south but inside under the dash, they are normally fine. It has supply from the round canister on the passenger shock tower to the HVAC unit, make sure it is good to and into the firewall, then follow the canister supply line back to the intake connection and make sure it's good and connected. If all the vac supply is good, the probable cause is the A/C control assembly its' self, could be vac line disconnected on it during all your work or the control is just bad.

Outside air intake flap should be open on Heat, Vent and normal A/C control position, closed when in the Off, Defrost or Max A/C position

[LLesniak]

I'd like to join in on this thread. I just pulled my Zagato out of long term storage (I lost my space, but that's another story!) and after installing the battery and fueling her up she ran pretty well on the way home. Now I'm going over the car to see what might need attention. One thing I found was a canister near the firewall that had a tiny piece of hose crumbling from one end and a plunger on the other. What is this and where should the other end of the hose go? My AC is working as are the other vacuum motors.The following photos give you an idea what I'm referring to and where it's located under the hood. Any help you can give would be greatly appreciated!

http://farm4.static.flickr.com/3536/3860039752_8198d5a43d_m.jpg
http://farm4.static.flickr.com/3495/3860039676_8549874ea8_m.jpg

[SubGothius]

One thing I found was a canister near the firewall that had a tiny piece of hose crumbling from one end and a plunger on the other. What is this and where should the other end of the hose go?

That's your heater valve. The vacuum line attached to the canister should run to a fitting on the left side of the HVAC box, down near the accelerator pedal (US/LHD).

Also, and it may be too late, but DO NOT move your dashboard temperature lever when the engine isn't running to provide vacuum, or you may break the cable housing-stop on top of the HVAC controls. Improvised repairs are possible, but it's better not to break it in the first place!

[davidb]

Cable: BTDT. Heat shrink tubing over sheath to increase OD.
Longer, wider diameter panhead screw, several drops of krazy
glue over HST @ top clamp. Seems secure, for now. New fan
switch no workie. Mr. cowl flap no open. Replaced heater actuator
above rack [just in case]. Time to hunt down elec. glitch for blower,
vacumn lines for HVAC operation. This week has been slowing raising,
adjusting the linkage rod UP via lock nuts. 2ND & reverse are slowly
engaging better. That crazy PS rack of mine has decided to NOT leak
[not a drop] last couple drives & that's w/o Seal Softner! I have faith
it'll spray again @ the least opportune locale. Back to the HVAC I go.

[davidb]

SubG thanks, I forgot that hose went allllllllll the way to the gas
pedal. J. Keller I don't know how or why but all that fabric wrap-
ped vacumn tubing inside [dash] was trashed. Re-route w/new
vacumn tubing, both hoses, the cowl flap opens! What a pain to
install. Now to get the blower fan to operate. New switch, still
nothing. Gotta luv these squirrelly cars . . .