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Scott,
Forgive me for being so long-winded, but this is my soapbox subject.
Does this describe your A/C problem: While going uphill, the blower GRADUALLY stops blowing out the center vents and the side vents (or wherever you have the A/C air directed); then, as you top the hill--and let off or ease up on the gas pedal--the blower starts pumping out cold air again, within just a few seconds. Does that sound like your scenario?
I have an '84 900S 3-dr. It does the same thing. I can tell you what is happening. It took me a while to figure mine out.
The blower speed is not being affected at all. Rather, it is the air DISTRIBUTION that is changed. Now, before you think I'm crazy, let me explain: the Old Gen. 900 HVAC (heating, ventilation, & a/c) air distribution is controlled by small flaps inside the dash connected to vacuum servo motors, in turn connected to your air distr. knob on the A/C controls. There is almost a maze of vacuum hoses in there, behind the dash fascia.
During long uphills, the vacuum canister is depleted--it's the white, small coffee-can-sized ribbed cylinder in the U.S. pass. side of the engine bay. It gets vacuum from the intake suction of the engine through a hose connected to the intake manifold somewhere.
It is the engine's vacuum which is affected (a lot of vacuum at idle, less vacuum during acceleration, almost none when floored, and certainly none in a Turbo when floored because turbocharger produces pressure into the intake manifold). Turbos have a check valve on the vacuum line to keep the turbo from pressurizing the vacuum canister and other vac. only gizmos.
If this problem occurred all of a sudden after owning your '89TC for a long time, then perhaps something is bad: vacuum check valve, leaky vacuum line(underhood or dash), or cracked (leaking) vacuum canister.
If this problem has been with you since you bought the car, as I bet it has, then you have two options: (1) live with it; (2) connect a vacuum pump.
I have a theory on how to fix it, and I've gathered the parts, but I haven't done so yet, so right now I'm doing #1 above.
If your Turbo cvt. has cruise control, then you may have all the right stuff already. I got a SAAB cruise control vac pump from a junkyard and intend to hook it up to my vacuum canister and rig up a switch to turn it on when I start uphill (when the vacuum will be depleted). I bought a check valve at the local Advance Auto Parts or AutoZone to keep vacuum loss down when the pump is off and engine is producing enough vacuum by itself.
I know, I know, I may be going overboard on this seemingly insignificant SAAB quirk, but I have lived with it for six years and two 900s now. Time to take action.
If anyone wants more details on how I plan to hook it up (or a schematic or picture of it once I get this done) email me at saabman84@yahoo.com.
Hope this (book) helps!
Micah in NC
'84 900S, 267K mi. (now parts car)
'84 900S, 214K mi. (daily driver)
'90 900, 65K mi. (Mom's)
posted by 216.77.233...
, Tue, 2 Jul 2002 17:04:57, Wed, 3 Jul 2002 07:41:15
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