I just purchased a 1985 500 SEL. The only problem I've had is the fact that it doesn't blow heat. It seems to be putting out heat, but it's not pushing air through the system. I'm assuming that there is a problem with the blower, but I'd like any input as to whether there could be something else wrong before I buy a new blower. Also is this something I can replace myself or should I take it to a mechanic.

Check for a blown fuse .. That chassis had a fuse modification kit where they installed a fuse holder outside of the fuse box, so if you look around the panels near the box, you should see a holder with a top on it. If not, it may not have the upgraded fuse kit and still have the original fuse in the box.
The original had problems melting the holder and wires , so if you find that to be the case , you or your mechanic may want to rewire using an exterior mounted fuse/holder.
The new holder allows for replacing the original 25 amp fuse with a 30 as the wires to the holder are a larger gauge.