I have a 1990 Blazer (350 EFI), while i am driving down the road the motor will just shut off. Sometimes it will start right back up and sometimes it will not do anything (no dash lights, starter does not engage. nothing). When it does start back up I notice the amp gauge flickering from 11 to 14 amps. I have checked and cleaned both battery cables, I replaced the ignition switch (the electrical one on the top of the stering colume) but I still have the same problem.

I can start it up and let it sit there and the amp guage will flicker and the truck shuts off.

Any ideas?

 

Get your alt and battery tested.

 

New Battery and Alt. Still same problem.

 

I had this problem in another vehicle. Check the Cable that goes into your distributor case under the hood. (Fuse box)...this might not fix your problem but it worked for me, by just tightening the screws to the main cable. Sometimes if it get shaken loose, it can shut down all power to your vehicle. Worth a shot! Good luck!