i was working on a 2002 dodge ram 1500 and when you turn the heater on the vents the passenger side is 145 degrees and the drivers side is 105 want could be the problem?

 

I'm no professional on this, but from reading a few posts on here could it be the blend door maybe stuck? Where you would get more heat from the passengers side and less on the drivers side? What about the ac? If you turn the ac on is it warmer on the drivers side? Don't know my friend, hopefully someone who knows a little more about this can chime in.

 

the heater fan/motor is on the passenger side so it is usually a bit more heat there, although that does seem to have a big difference, as cwboyjohnny24 said it could be a blend door or some of the ducting could be detached
do you notice a difference in air amount coming out?
i had a mouse chewed a hole in one of my heater ducts, check the cab foot space for excess air when your upper vents are on.
most likely a leak or stuck door

 

i kno for a fact its not the blend door issue but idk