Any idea how I could get the AC to start blowing again, or what could be causing it not to blow? Won't even blow with the truck running while not idling. This truck uses the Detroit Optimized Idle as well for idling, if that makes a difference.
Dash ac must be on. Mine also has a switch on the dash for sleeper. Then adjust fan speed on sleeper panel. Unless you have an APU with ac? Whole different story.
Is the fan working? Does it blow at all? No? Blower motor. Check your fuses first. Yes, it’s blowing, but it’s hot air. Under the hood, there may be some heater valves. There would be two, one for the front blower, one for the rear. Turn the rear valve (you will see the water lines going towards the sleeper while the other stops at the firewall) off and see what f it blows cool now.
