I just found the article about the heat issue from some guys 2006 equinox.http://www.handymanlyness.com/archives/auto/repair/climate_control/heater/2006_Chevy_Equinox/air_temp_blend_door/replace_actuator_06_Equinox.htmlBTw I have a 2006 Chevy Equinox LT AWd with 115k on it. I have a few questions for the article writer or anyone there that has had experience working with this model vehicle in regards to lack of heat. I have been dealing with this issue for 4 months now, and its starting to get cold up here in maine. Its a chilly 10 -15 degrees in the morning and my windshield is always frozen. So please HELP ME. I got a quote from a GM dealership for 973 for a heater core replacement. Just read this article and wondering if its a similar fix. okay so first thing is first. 1. (NOT SURE IF THIS IS RELEVANT) First noticed an issue when I had my ac on during the summer, for about 10-15 minutes, when it was parked I got back in and it was on red blowing hot air. I shut it down and it was almost smoking, popped my hood and let air out of my coolant reservoir. Started to drive and it cooled back down, realized that my ac pump was malfunctioning and it may be causing the engine to over heat. Again not sure if this is relevant or not. 2. As it got colder and colder I realized my car wasn't getting warm no matter how long I left it running. I would be driving along and it would just blow cold air. Then one day I was letting in run while I was waiting for something, I was traveling a little but not a lot, and I stopped to drop someone off and it started to smell, it was almost on red again and blowing nothing warm. Again just let it cool down and drove it and it came out of it.Here and there I would get some warm air but never anything hot like some cars produce. Anyway the car consistently got hot every now n then sitting just in traffic.3. I decided to put some fresh coolant in it, Prestone/ACDELCO GM 50/50 orange stuff just like what's in it. it took about a half a gallon strangely enough and then it started to blow warm air again. Since then and that was about a month ago, it has blown some warm air every now n then, like if I let it sit or just not have the air on it will blow some warm air and then the air would go cold again within 30 seconds to a minute. Never long enough to warm it up.4. Just today, I got stuck in a bank bc I veered off the road on accident( DONT ASK), and in the process of getting unstuck it started to overheat, it actually got so hot it spewed out the over flow it was smoking and running bad, almost like the engine didn't have any power. Got it unstuck and then let it cool down. During this event I realized that neither of my fans in the front are on even though the engine is boiling hot and over heating. the heater core lines are hot, well one of them is boiling hot and the other is warm. I got an alignment today and the tech said one of the lines was ice cold and that they think a coolant flush would only cause more issues, another said that I should do a drain and refill to put fresh coolant in. However I think my issue is the core or something else. I do have a thermostat, and I will be replacing that soon, however I don't know why my fans aren't on. Something with a sensor must be interfering somewhere. I saw this article and was very intrigued. Please send me anything you think would help, I will probably be trying to fix this on my own with a mechanics help not a garage. Both the heater core and the air temp blend door.