On you condenser, there is a fan that looks roughly like this: http://www.amazon.com/Dorman-620-035.../dp/B001CA8W6Q
Make sure it's moving when the a/c is on. If it's not, make sure to check the fuses before you consider replacing the fan. That's the most likely culprit for the a/c problem.
As far as heat, the problem usually comes from low coolant or air in the coolant line, stuck open thermostat, or at the very worst, a weak water pump. Does your truck come up to temp normally, and hold temp properly? No overheating?