jeremytn86
Newbie
So, I have searched here, and the web, trying to find the same issue and/or an answer. I have a 99 K2500 Suburban 6.5 diesel. Front and rear heat is nice and hot. When I put it on defrost though, it is barely warm. Some backstory, I had the blower motor and resistor changed out by Midas when I was working in Michigan. They said a lot of stuff in there was melted. I was working 7 days a week, 12 hours a day and staying in an Airbnb, so I didn't have time to fool with it. Later, I replaced the little circuit board with the control knobs for heat and position on it in the dash. Also, very very seldomly, the blower will stop completely, no matter the position, but then start back up within a few seconds. I fear the resistor or motor is going bad again, though that was within 2 years ago, or they did a horrible job. Also, if someone is fairly bored and likes to teach, I would love to know about the HVAC system as a whole. I have been trying to read up on it, but I am confused. There are three gear assemblies, with three separate actuator modules? One in passenger side, one in middle, and one in driver side? What does each do, what is where? The blend door is by the driver's side and controls the temperature? The mode door is in the middle and controls where the air is being blown out of? The recirc door is in the passenger side and controls if the air is fresh or recirculated? Or is all that wrong? Anyone have any pictures, schematics, diagrams, videos, or write ups relating to any of this? Thanks in advance.