From time to time when we start the Expy up the a/c will blow hot air like the heat is on. We then have to shut the truck off and start it back up again to get it to blow cold air. Any ideas wheat might be causing this?

 

I had a 96 Explorer that did that too...
My solution was to turn the temp **** to hot then cold a few times, and it would then get cold

I thought it could be a vacuum leak in the heater controls

 

Mine just stops working from time to time. Shut the engine off for a while and it starts working again on start up. Also, While driving it will blow a momentary blast of air.

 

Ok, the truck did it again and I was home to check it out. The driverside air is blowing out HOT air, but yet the passenger side is blowing out the COLD air like normal. I wouldn't even know where to start looking to fix this. It doesn't do it all the time so by the time we would ge it to a dealer it would be working fine. Any suggestions?

 

Do you have manual climate control or dual - diff temp each side?

If manual, I cannot offer an explanation.
If dual, seems the blend door for the drivers side is not working all the time.

The blend door is responsible for making the temperature you select by blending heat and AC. If its closed or not working on either side you get the symptoms you're experiencing

 

I had the same problem with my MB R350 last year during the winter months. Changing the blower motor, did the trick for me!

 

I have the dual climate in the truck. I read a TSB about the F series for this problem but I didn't read about it including the Expy. Do you think this will cost me or be covered under the TSB?

 

Dashes are a little different in the F150 vs the Expedition.
I dont find much on replacing one in a full size ford, but here's a nice write up for an Explorer that should give you an idea of what you could be in for.
I dont think its a terribly expensive part, but labor is the killer

How To: Replace Blend Door Actuator in 3rd Gen Ex. - Ford Explorer Ranger Enthusiasts "Serious Explorations"®