Chevrolet Repair: 1989 Chevy Silverado k3500, chevy silverado, transfercase

Question
My 1989 Chevy Silverado k3500 won't shift into 4 wheel drive. It has an automatic transmission and when I try to put the truck into 4 high the indicator light doesn't come on at all, when I try to put it into 4 low it won't shift at all. What could be the problem and how do I fix it?

Answer
HI JOHN,,WE I AM NOT AT WORK SO I HAVE NO INFO AT MY DISPOSAL..BUT ARE YOU SAYING THAT WHEN YOU PUT THE TRANSFERCASE IN FOUR LOW THE TRNAMSISSION WILL NOT GO INTO GEAR AT ALL..IF THIS IS THE CASE IT SOUNDS LIKE YOU ARE IN NUETRAL ON THE TRANSFERCASE LIKE IT IS IN THE PTO MODE AND YOU THINK IT IS IN LOW..TRY PUTTING THE TRANS IN NEUTRAL AND THEN TRY TO PUT THIS IN LOW RANGE.THE ONLY WAY THE TRANSMISSION WOULD BE AFFECTED BY THIS IS IF THE TRANSFER CASE IS IN NEUTRAL.IF THIS IS THE CASE IT SOUNDS LIKE THERE IS A PROBLEM OIN THE FRONT AXLES NOT ENGAGING...ALSO GET BACK TO ME IF THIS IS A SHIFT LEVER ON THE FLOOR OR ELECTRICAL SWITCH TO ENGAGE THE 4WD..CHEVY CHANGED FROM LEVER TO ELECTRIC AROUND 88 TO 90 I FORGOT ..SORRY..GET BACK TO ME IF YOU CAN.....TOM