Chevrolet Repair: 93 Chevy 3500, vehicle speed sensor, chevy 3500

Question
93 chevy 3500 Started it up the other morning and the brake light was on let the vehicle warm up and it would not shift out of first gear, and the speedometer would not function, someone suggests it may be vacuum would like to know your thought.  Thank You

Answer
Hey,

 Lets look at as two separate problems in which I have a feeling it is.


 Depending on what transmission it is there is a vehicle speed sensor that the dash AND the transmission use to indicate and measure road speed.  This sensor is at the back of the transmission near the tail stock.  It sounds like you have a bad VSS and should probably have it tested and replaced.
 The Brake Light could be illuminated because of the VSS, the emergency brake pedal being down a bit or the proportioning valve.  There are several different options from RWAL to 4WAL abs systems so what I would do first is pull the emergency brake release lever and pull up on the pedal with your hand.  As cables get out of adjustment they get loose and rattling down the road will cause the pedal to drop and close the light switch.  If the brakes feel and work well then the proportioning valve probably didn't kick over but you should check fluid and make sure both reservoirs are full.

Wayne