Heat is not coming out of the left vent - 1990 Volkswagen Cabriolet

look under dash to make sure vent door is working proper

This is becoming a known problem. The heater core is plugged from the factory it must be replaced. I am a service writer at a dealer and we are putting heater cores in 200 and avengers left and right.

You likely have a faulty blend door. It could be electrically, mechanically related, or even a broken door. It may be the blend door motor, or possibly the temp sensor.

check to make sure the carpet isn't blocking the right side vent. Both vents come from the same tube so if one is working the other should be also.

check for vacuum leak some of the switch are vacuum controled

not sure on model but it sounds like the selector wires have come off these are the wires conected to the blower selecting where the heat comes out from eg to vents foot well or windscreen or the little loops that the go around have snaped or come off hope this helps

I really can't be sure off hand, but what you wrote looks like the control valves are sticking(these flaps allow air to go different directions at the vents). its located at the heater core(towards the left side of the heater core) under the plastic just under the dash. you can manually move them, encase they are stuck, they do stick sometimes. while checking the vent doors, make sure your vacuum lines are connected. also check to make sure your vent hoses are tight. I hope this helps

The duo-valve needs to be replaced. It controls the coolant flow to the heater core. They get stuck open or the rubber diaphram comes apart and no longer seals. In either case it allows the coolant to enter the heater core and causes hot air to blow out of the side dash vents. See if the inserts are available separately.

I had the same problem and mine was a small plastic tube on the right side of the engine, just a little back of the intake manifold. It had collapsed from the heat coming off the engine. I shortened the tube and have not had any problems since. (make sure you sit in the drivers seat for left or right)

Yes go to you have to get the codes from your ATC controls first...Hold down the A/C button and the Recirculating button at the same time and while holding the two buttons turn you left temp. control up. It should give you codes if not then it will just read 00. Once you get those find out what they mean...20, 46,52,or 54 means you blend door(s) are stuck down and have to come up to allow heat to flow. Go to www.heatertreater.net and it will tell you how to replace it or in my case I just fixed it by putting a screw in it to hold the doors up....But hey i'm cheap so i like quick fixer uppers!!! Try that and lemme know if it works...