Lennox heat pump / condensor 4-5 years old. Condensor fan runs for 10 minutes and shuts down, and compressor continues to run until overpressure cutoff shuts system down. The cooling fan motor was really hot at shut down so I changed the fan motor. With the new fan motor installed, the fan still shut down after 10 minutes. OK, Maybe its the capacitor? I ordered a new one from an Internet parts store, but could not get part numbers off the old one! The new one which cost $158.00 ( a 3 pole type) doesn't even start the fan. I have no part numbers to help order a new one. Before I go through any further research to find the correct capacitor, Am I even on the right track to repairing my unit? Does this sound like a capacitor problem?