Rod,
I balance ceiling fans by just taping coins to the top side of the fan blades. I just tape a coin to one blade an turn on the fan. If the vibration improves, I adjust the coin count until the is no vibration, and if it is worse, I move the coin to the opposite side blade. This takes a lot of trail and error, and a lot of moving of the weights, but it works very well if you are patient, thorough,and use a good tape like duct tape.
If your front A/C fan is noisy, that is usually caused by either a shaft bushing or bearing.
Gerald