Reasons A Car Heater Is Blowing Cold Air. The most common reasons why a car heater is blowing cold air are due to a low coolant level, a malfunctioning thermostat, broken heater flaps, or air in the cooling system. It can also be caused by a clogged heater core or faulty heater controls. Here is a more detailed list of the common causes of why Steveu Discussion starter. 3 posts · Joined 2021. #1 · Jan 12, 2023. The heater in my 2005 TDI 2.0 is not blowing hot air. I took it to a radiator shop and they said the heater core was not clogged. They blew it out with water pressure. All functions (mechanical) work. AC, defrost, heater all change as they should. MirceaM. 250 posts · Joined 2012. #2 · Sep 7, 2013. if they both dont work and its not the bulbs then it means that you have a fuse or relay blown. check the fuses but most likely there is a relay blown. maybe someone might fin the correct curse of action. L. 1. the first is to try to dislodge the clogging, and there is a DIY I wrote (and added others' info to) in the Information Base forum. do a search in that forum on "blues" authored by me. 2. the other is to remove the dash and replace the heater core. First reply to the thread was your really good DIY for clogged heater core. Have a 2015 Amarok, the passenger heated seat is not working, it switches on ok, yellow lights come on, but after about 10 seconds the lights go off and won't switch back on again until I switch off the ignition and back on again, whereby the process just repeats itself. Ive checked the plug connectors under the seat, all good. 17K views 9 years ago The heater on my car was only working at position 4 so I took the heater resistor out which is located just above the passengers feet behind some foam. I guess the 2009 B6 Passat Highline That was an excellent help, thanks for putting that together! What a pain to access the motor, no kidding! My issues were a "hunting for position" V158 (left temperature flap) and sometimes also the V159 (right temperature flap) made that clicking noise, motor trying to catch the setpoint 1. remove lower-outer grille held in by clip (inboard) and screw (outboard) 2. lay on your back looking up. 3. remove screw from underside of signal assembly. 4. gently pull assembly out of bumper. 5. do whatever you need to do. reverse process to put back together. Thanks alot, I will give this a go tomorrow!!:thumbup: B6 Passat heater not getting hot. - 07-09-2014, 09:30 AM Hi Guys, My heater has has started to only heat up when it wants, I can set it onto max heat and it will blow cold and then starts blowing hot maybe 5-10 mins later??? Dealer Price. $ 192.98. Hvac blend door actuator. 2015 Volkswagen Passat. Genuine Volkswagen Part - 561907511B (561-907-511-B) 3mZ621.