Question : Problem: how do I extend a dsl modem port 1500 feet?

I have cat-5e cable in place (1500 feet) and the cable
has been tested, I don't seem to have enough power
out of the dsl modem port to drive the signal this far.

Answer : Problem: how do I extend a dsl modem port 1500 feet?

If you can't easily place and power switches in all the places needed, you may want to think about running fiber optic cable. There's extra cost and complexity with converting the signal from Cat5 to fiber and back, but fiber can run much longer distances without repeaters.