As of recently my 1990 740 GLE wont shift into overdrive. It was acting up from time to time and not shifting into overdrive, but now it wont go at all. The switch on the shifter still functions and turns the light on an off on the dash. Although that did stick a while back. Previously when I had a similar no overdrive issue the light would remain lit on the dash and pressing the button would do nothing. Evuentally enough presses or time, Im not sure which would finally make the light go off and then let it shift. But now the switch and light seem to function normally. I did try replacing the relay with a used one from a car in a local junk yard. When I did that it shifted for about a day, but wasnt consistant. Is it possible to have grabbed a relay that was bad also?

Is it possible to over ride the relay and lockout to bypass it and see if that is the issue? Or over ride it permantly so it will shift into overdrive without that extra mess? If I did that would it cause any other problems or harm anything by over riding?

Need help desperatly.....

Thanks