91 accord LX. When I turn on the ign. the charge light dosn't come on. The light dosn't come on when the engine is running. I disconnected the four prong connector and grounded a blue/white wire(haynes Manual) and the light comes on. The battery is fully charged and shows 12 volts, with the engine running it reads 15 volts. Under a load it also reads 15 volts. What is causing the light to stay off with I first turn on the ign. All other light work properly.