In my 79, the only heat comes from the defroster. The two vents just pump cold air... has anyone worked heat to those?
If you are getting heat out the defroster vents and not the other ones then you must have the pipes disconnected.
On my 82, there are 2 round side vents and behind them are a black approx 1" diameter tube that connects to the back of the vent,(you need to remove that small piece of the dash and pull the piece with the vent out to access it better) has a "Y" with a shorter clear plastic tube that leads up to the dash vent and lead across the back and into part of the heater box on the floor,behind and on the side of the console. I noticed one day I was not getting any air cirulation out of the drivers side, looked under the dash and that tube was gone, just compared it to the other side, went to the junk yard and found one out of a 79 (mint condition, don't think thats a hot item), came home installed it and now I have air flow. Look under your dash and see what the situation is, good luck. Hope this helps you out.
79-83 heat duct information old post I know. but trucks with AC had outer vents ducted into central system. Trucks that did not have AC did not. those vents went straight out of car into cowl box. so it depends on AC vs non AC. I know in VW's there were ways to re duct those outer vents to the heater system. Easiest thing to do would be get the duct work and center vent out of a factory A/C'd truck and use them. If not I'm sure someone handy could still get them blowing hot air with some flex duct and couple pieces of plastic. looking at Schematic trucks with AC had a different center vent. it is where the outer vents Y 'd off central system. non ac'd trucks vent did not have side openings. I have exploded views of most anything if anyone needs particular diagrams. If someone did this It would be beneficial to find more powerful blower.
