1991 gmc van won't crank over.

1991 GMC C3500
141,000 MILES
Avatar
JTDBA
  • MEMBER
  • 1 POST
For months, the truck would occasionally failed to turn over on the first try, usually when hot. Then it failed all together. So far I've replaced the starter, battery, ignition sw, and neutral safety sw. The key still won't provide power to the starter solenoid. There doesn't seem to be an ignition fuse.
Could a defective ECM be at fault or should I be looking for a short?
Aug 31, 2011 at 3:52 PM
Advertisement
Avatar
RASMATAZ
  • ✓ASE Certified Mechanic
  • 75,992 POSTS
  • ASE Certified Mechanic
Check if its a security issue if not recheck the ignition switch-try this cross the starter motor solenoid terminals and see if it cranks over the egnine-
Aug 31, 2011 at 3:58 PM
Avatar
JDL
  • ✓ASE Certified Mechanic
  • 16,098 POSTS
  • ASE Certified Mechanic
The purple wire at the starter solenoid should be hot with the key in the crank position. Note picture below.

You may have to check feed to and from the ignition switch.
Image (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Aug 31, 2011 at 4:04 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.