2003 Venture Headlight Switch Wiring Diagram

Trying to troubleshoot an issue with the instrument panel not being lite during night time in any Headlamp swithc postion (auto / park / Headlight). For several years the Venture used the same headlight switch which is an ACDelco D15001G / GM Part # 10409580. I have the service manuals for the 2003 Venture but need the wiring details of the headlight switch. I am trying to figure out why terminal H (IP lamps) is not getting voltage even though terminals N, O and R have battery voltage. I have tried all three positions of the headlight switch. New switch did not fix problem. IP lamps will work at startup sometimes and stops on the next startup. Something is causing the headlight switch not to allow battry voltage thru the dimmer switch to reach terminals H and G. I then thought it was the connector on the harness but can not get the system to fail and battery voltage is getting to the switch terminals not just the connector terminals. Any thoughts would be appreciated.
Steve