Originally Posted by welbo97

If the hoses are the same temp (hot) then you've got good flow through you cores. Next thing to check is your tstat. My truck has a 190 deg tstat in it. You should have close to that temp on the tstat housing. The ir thermostat like harbor freight sells is a good tool to measure it. If you verify your tstat is working, I think you should check your blend doors. The rear core is accessed thru a compartment at the rear of the vehicle on the drivers side. It's a door just like the one that hides the jack on the pass side. Pull it off and you can see the whole unit.

I'll look up what actuates those doors, front and rear and let you know how to test, unless someone beats me to it. I'm guessing when I say the front is vacuum powered and rear is electric.