no matter where I change the dial, I only have defrost. Googled it and everything points to vacuum lines. was hoping it would be easy to find but cant find anything.

 

What YEAR Ranger?

Yes, you have no vacuum in the cab, air direction vents use vacuum "motors"
Defrost is when all "motors" are off, OR...........there is no vacuum

In the Engine bay, passenger side, you will see a black and a grey hard plastic vacuum line coming out of the firewall, they look like wires, but they are vacuum lines

The Black one will run to the front passenger side(1995 and up), to a black plastic Ball, the vacuum reservoir, may have to look up from under the truck to see it
This black line often breaks, cracks or melts near exhaust, easily repaired with rubber vacuum line of correct size

If black line looks OK then the vacuum reservoir ball may be cracked, have a look

There is another vacuum line coming out of the ball, it runs to the intake manifold, the vacuum source, this line can break or get unplugged