Our ceiling fan was working from the wall switch, but our renter pulled too hard on the chain and broke it off at the motor assembly. So we could not adjust fan speed. We took it down, replaced iwith a new 3 speed fan switch - checked to make double sure the wires were in the right place (4 wires, two top and two bottom) put it back together and now the fan won't turn - light comes on, but no rotation. What else should we check?

It's possible you used an incorrect replacement switch-- order one from Harbor Breeze-- or a wire is loose. See:

Ceiling fan pull chain replacement and repair - Ceiling Fans N More (http://www.ceiling-fans-n-more.com/ceiling-fan-pullchain-replacement-and-repair.php)