Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Alt Light
Thread: Alt Light
View Single Post
  #1 (permalink)  
Old 12-08-2012, 12:02 PM
scholman scholman is offline
Join Date: Aug 2003
Location: California
Posts: 908
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 3 Posts
Alt Light

The vehicle is a 1976 GMC Sprint, 350

I start the engine and it runs like a top. I rev it up to about 2,000 RPM and the Alternator light comes on. I thought it was the alternator so I put a volt meter at the battery with the car off. Voltage reading is 12.35. Start the engine and the voltage is 12.28. Engine running no Alt light. Rev it up the voltage jumps to 13.84 AND that is when the light comes on. As long as the alternator is charging the light is on. When I disconnect the two lead plug going to the alternator the voltage drops to 12.8 but the light is out. Reconnect the connector and the voltage stays the same until I rev the engine. Then the voltage goes up and the light comes back on. I have not run into this before so any help would be great.
Reply With Quote