Transmission

TURN ON IGNITION SWITCH IF IF READ OD OFF ON DASH PUSH BUTTON IF LIGHT GOES OUT SWITCH OK, IF LIGHT BLINKS WHENOFF YOU HAE TROUBLES. There is an overdrive main switch switch (button on shift lever.9 Push down plastic sleve at botton, remover 2 screws, test for resistance between terminals 2 and 4 ( which will be on left when hump part of connector at top If resistance oo open, off O for continuity switch ok.of no good, could be bad switch.,@, it could be a bad speed sensor,, , there is also and Overdrive clutch speed sensor on drier side of bellhousing. It is best to have a transmission person check these.