Heating problems...

Roger that!
Im off to nap land,gonna roll hard tonight

 

Look for the valves first. If there are no valves then cardboard will not work. Doubtful an 06 will have cutoff valves unless they were spec'ed when the truck was ordered as cut off valves are very old school and not needed with the newer engines and heater and AC controls equipment. Sounds like the control valve for the front hearer is gone and it's about a 1.5 hour job to replace on top of the wait time.

A note about using cardboard: Have you ever noticed that all the pre made covers have the hole in the center to allow air to flow through? If you do use the cardboard trick don't cut the board from the top, sides or bottom! Start in the center in front of the hub or you will cause uneven air flow over the fan wearing out the hub causing the fan to quit when the bearing wears out. THAT'S a truck stopper worse than a heater problem! Start with a 6" hole and make it bigger until the temp stays around the 180* or the normal engine operating temp you usually have.

 

I would check the heater control valve that is inline with the heater core that provides heat to the front part of the truck. If it is an older style it will be cable driven. If it is newer it might be electronically controlled (more expensive). If they smell a sweet smell coming from the vent in the front of the truck and are losing coolant than it is a heater core that has gone bad, but you didn't mention them losing coolant so I don't think that it is this.

I believe that Rollover the Original has got the right idea.

You can still find shutoff valves on brand new trucks. We have brand new trucks at work that have them on there.

 

So there was no effort on the drivers behalf to fix their lack of heat ?
Were they just sitting at a shop and you posting questions here?