AC Vent Blockage

"Problem #256 on today's list John." for those of you who get the reference. :clapping:

Anway, the first the problem is that I have a basic Non AC system. Although I can live with this.

What I can't live with, however, is the fact that only these 2 vents and the defroster vents are blowing air.

These vents do not blow air, with the exception of the middle one (under AC controls) that just barely "trickles" air out.

Anyone have any ideas why the others don't blow any air whatsover? I'm all ears as I've tried running the system on hot and cold, at all speeds, and when the truck is first started, and then later on after being driven for over 30 minutes. All to no positive results. :dunno:

your blend doors are not working properly, i would check to make sure your heater controls are getting vacuum

your blend doors are not working properly, i would check to make sure your heater controls are getting vacuum

How would I go about doing that exactly? :hmm:

Your HVAC vacuum lines originate from your intake manifold, make a run around the back of the head, thru your vacuum reservoir behind the pass. bumper. The lines run along the passengers side fender and dive under the battery tray to the reservoir.

The black line coming out of the firewall is the HVAC vac line that controls your blend doors. If you have a vacuum leak anywhere in this set-up you'll get default air out of your defrost.

Follow the lines all along that route looking for splits, breaks, wear spots (aka any leak). I use the smoke test, blowing some smoke into a line or two usually pinpoints the leaks. When you find leaks I suggest that you replace the whole line or group of lines. Duct tape and cheapo repairs might work for a bit but the vac line is so cheap, why screw around, old line will just crack and leak again.

Your HVAC vacuum lines originate from your intake manifold, make a run around the back of the head, thru your vacuum reservoir behind the pass. bumper. The lines run along the passengers side fender and dive under the battery tray to the reservoir.

 

The black line coming out of the firewall is the HVAC vac line that controls your blend doors. If you have a vacuum leak anywhere in this set-up you'll get default air out of your defrost.

 

Follow the lines all along that route looking for splits, breaks, wear spots (aka any leak). I use the smoke test, blowing some smoke into a line or two usually pinpoints the leaks. When you find leaks I suggest that you replace the whole line or group of lines. Duct tape and cheapo repairs might work for a bit but the vac line is so cheap, why screw around, old line will just crack and leak again.

Hmm, sounds simple enough, and I wouldn't doubt there's a leak somewhere. You know off the top of your head how much it is to replace the entire line?

...about fifty cents a foot.

2 feet will cost you a buck, maybe less, maybe a bit more. The engine vacuum harness will cost about $45, but that has nothing to do with the A/C.

make sure you didn't just knock the vacuum block off your heater controls, happens alot when removing/installing a radio

make sure you didn't just knock the vacuum block off your heater controls, happens alot when removing/installing a radio

Funny you mention that.... Been tinkering in that department for a good week now. What does the vacuum block look like?