Prostar heating issues

Well, you said the lines are hot, the heater hoses, is the valve under the hood all the way open? Have you had any coolant issues, draining of the coolant? Maybe the heater core is plugged, you may try back flushing it or blowing it out with air. Or, the blend door, did you calibrate the actuator when you installed? There is a procedure to get it working properly, it is not plug and play. If it is not any of that, and the blower motor is working, more than likely it is time to replace the heater core. If it is, shop around, try FleetPride. I found mine at a Peterbilt dealer for $200 shipped overnight. International wanted $750 for one, which is a complete rip off.

 

Another thing, if you are having AC issues. Find the ambient air temp sensor and dig it out and place it up on your windshield wiper cowl. You should have air after doing that. It took me four years to get AC in my truck, that sensor was buried under my radiator and is tied into your AC. I dug it out of the harness, rewired and moved it, I have had AC since, it has been nearly a year now.

 

Is the fresh air actuator working? That is located under the hood to the right of the air intake box. You have to remove the windshield wiper cowl to get to it. Just a thought, they rarely fail, but worth a look. these ProStars have the worst HVAC system known to man.

 

Oh, on the blower motor, their is a harness that needs to be added if you do not have it. It was part of a TSB potential for fire. Dealer should know about it, I don't have the part number handy. It cost around $25. Plugs in between the harness and the blower motor. Also, the 30 amp breaker for the AC, replace it with a 30 amp fuse, and keep a few on hand, they fail often, even though they test as working. Been there, and done that.

 

Yep, that or the heater core is shot. Been there and done that.