So I have a 2008 Tahoe LT with 145k wish miles. Everything was good until a couple months ago my tailgate is having gremlins. It is not a power lift gate first off . The problems i am having are 1 the lift gate won't open. When i hit the button i can hear the actuator trying to do its job but it won't release( i have tried swapping in another to no avail). The wiper does nothing the glass won't open unless i shut the headlights off (with the headlights on it does the same as the gate actuator and the plate lights flicker). Any ideas???