I have an 08 1500. The blower will stop working intermittently. Sometimes i turn the truck on and it works but 10min into a drive it cuts out on all speed settings. Sometimes it doesnt work from ignition until halfway through the trip. Also it will blow on a setting from time to time but increase speed as i increase speed. I work on artillery in the army so i can trouble shoot but im lost with wheeled vehicles. Any ideas on where to start?