1994 GMC C3500 brake light/transmission

1994 GMC C3500
Avatar
BEDFORDDAN
  • MEMBER
  • 1 POST
Electrical problem
1994 GMC C3500 V8 Two Wheel Drive Automatic

dash brake light is on. however it goes out sometimes and when it does truck will not shift out of first gear. What is the connection?
Apr 14, 2010 at 10:09 AM
Advertisement
Avatar
DR LOOT
  • CERTIFIED EXPERT
  • 2,311 POSTS
this could be quite a complicated problem, the only thing I can think of is due to the fact that the cruise control is hooked up to the brake light switch, and the vehicle speed sensor in the transmission is connected to the cluster electronic speedometer. I don't have enough information to help, I need to know if you lose the speedometer when you lose the transmission? the only way the transmission will not shift, is if you lose the speedometer, .or the VSS (vehicle speed sensor) has malfunctioned.
Apr 23, 2010 at 5:27 PM