Very strange problem with the starting

[Hummertech]

Las Vegas is right, and that may be your only problem. Ignition switches do fail quite often on these trucks. They will send proper voltage on some circuits, but intermittenly lower voltage on other circuits. If all of your problmes are not cured by that. I would check 2 other easy things. 1. make sure your battery cables are not corroded. A lot of people will change a bad battery and leave a lot of corrosion on the cable. That can cause intermittent problems. 2. Check all of your grounds. Especially if there is any area the vehicle has been tampered with, wrecked, etc..