I have a 2005 Silverado 1500HD with an intermittent horn. I cannot pass state inspection unless the horn works. I confirmed the horn is good, the relay is good, I replaced the steering wheel horn contacts (behind the airbag) and finally replaced the clock spring. Horn still intermittent. I checked the grounding of the steering wheel itself and it ranges from 0 ohms (good) to 1500 ohms (bad) and changes as I turn the steering wheel. I need to know how the movable part of the steering wheel is grounded so I can fix it. Any ideas ???