I purchased a Garmin 430 from an avionics shop that has been tested. It came with a wiring harness that was just cut from the components. Now I am trying to decipher the installation manual to decide how to connect this unit. Are there any books, or materials that would be helpful in finding out what all the terms means and how to apply them. Example 10 altitude out pins,com mic audio lo, com mic audio hi. I have thought about having an avionics shop wire this for me if the group thinks it's too complex. I did do a electronics correspondence course many years ago and do understand basic electronics. Thanks Randy