HVAC assistance for a new 944 owner
 

Good evening. Or morning. I have lost track at this point what everyone else's time frame is.
In the scope of this post, let me elaborate a little. I recently acquired an '87 944. It is the NA non-turbo, 2.5L. To my knowledge, the vehicle sat from the late 90s until I got it, and this vehicle was a total Barn find with most of the mechanics in excellent condition. The title has 106k on it, while the Odo is broken at 97k. Already know I have a busted gear there and am working on that.

Work done so far.

• New strainer, fuel pump, fuel filter, and the soft lines that attach to the hard line leading to the engine bay
• New timing and balancing shaft belts, with replacement idler pulleys
• New coolant hoses and a coolant flush (previous owner used Dex-kill, and the outlet from the heater core outlet to the thermostat housing was completely clogged with buildup)
• Rehung the power steering pump, and replaced the missing belt and tensioner for it.
• New Distributor Cap, Rotor, Spark Wires, and Plugs.
• New oil and filter within the first 100 miles of actual current driving.
• New Speed and Reference sensors. (The ones originally there were torn up as the mounting bracket wasn't tightly bolted down, unknown to me)
• Coolant Temp sensor Properly re-wired to original state
• New double din GPS Bluetooth touchscreen radio (needed the functionality so more safely drive the stick shift)
• New inner and outer shift boots (spruces up the interior, making it look less rundown)
• Vacuum lines done properly as close as my research could find (stumbled over a diagram for an 86 NA non turbo that was practically identical to what I was looking for in my 87)

Now that we are on the same page, here is what I am currently facing. This car is going to be the new daily driver for me. As such this will need to be State Inspected (currently running on antique tags to avoid the risk of being pulled over and ticketed for no inspection stickers). As a former mechanic, and general car owner, I know what will be looked for when they do go through it.

• Passenger Fog light Lens is shattered
• No third brake light in the hatch (the housing itself is completely missing, though the wiring itself is still there.)
• broken Lug stud (on order)
• No functionality on the Windshield Defogger.

This brings me to the actual reason for posting to the forums. Hopefully I can get some assistance with this. After fixing the vacuum line issues between the HVAC controls and the Heater Core Coolant Valve, I now have the system nearly back online. Would say it is close to 85%. Flappers from foot-well vents to upper dash vents work as they should, the blower motor works on all speed settings, and the defog button works as it should (overriding the controls for full blasting heat). With all of this functionality, there is the problem that No air is moving through the top dash vents when the selection knob between the central vents is slide all the way up. Air comes out the side vents, at a faster pace (evidenced by the increased sound pressure) but that is it. there is no air against the windshield.

Hopefully some of you good people here can give some pointers or actual knowledge of this issue for a newbie owner to knock out another bug in his new and fun driver. So, thoughts?

You won't believe this: for the first five or six years of owning my 951, I always had the HVAC sliders in the wrong position. I assumed that all the way to the right meant full open for vents.

One day, I read the owner's manual HVAC section. Duh. I realized it was the opposite.

From your description, I assume that you get air from the defog vents sometimes but not when that middle between-the-vents lever is up. I believe that lever directs air from the central vents up to the defog vents. If the central vents aren't "on", I assume there's nothing to re-direct.

You probably know this, but just in case, make sure the horizontal levers are all the way to the left first

Thanks for the help. Yes, i have noted the positioning of the horizontal sliders, and their results. Even with both of them slid to the left, of full air flow, i still get nothing from the defog vents when the vetical adjuster is slid all the way up. The only thing is a greater air pressure as the only exits are the defog side vents on either end of the dash by the windows. I would think there should be air coming from the top dash vents when defog is engaged. Am i wrong in this assumption?

When you slide that central knob up, does the air stop flowing out the front vents? That's one of the simplest parts of the system - it's completely manual and I'm pretty sure it's just moving a flap.