During trip warning lights began to illuminate 1 by 1, dash lights went out, running lights went out, engine finally quit. BUT THE BATTERY LIGHT NEVER CAME ON until truck died. After checking belt, connections and all the basic stuff I put my jumper box on the battery to let it charge up. It started and everything was fine for about 4-5 miles until it happened again. I did the battery boost and drive thing about a dozen times until I got home pulling a 42' trailer. Battery tests fine. I have the same voltage at the alt as at the battery but no increase in voltage when running. I'm leaning towards a bad alt but the question in my mind is why doesn't the battery indicator illuminate until after engine quits? Something is making the hairs stand up on my neck about this and I don't want to just start throwing money at it. Any thoughts out there?

 

No replies or comments? Please help me with something.

 

 

A little side note,
If the alt is putting out 1 amp the light can go out, but if the vehicle is using more than what the alt is putting out the light will not illuminate.

 

Hayapower: The voltage is whatever the state of battery charge is both at the battery and alternator.

hanky: Thanx for the "side note". Based upon how I'm understanding it, it kinda defeats the purpose of having a battery indicator because chances are the vehicle normally will be using more than what the alt is putting out if the alt is not putting out anything. Especially if running with lights on. I'll be putting in an add-on volt/ammeter because of it.

I'm seriously hoping it's not a PCM issue, as that is what controls the internal regulator. (so I'm told anyway)

 

Those of us that have some understanding can see this, and it's no wonder they call that an " idiot lite."

Costs always come into the picture and a lot depends on which indication you use and where you place it in the charging / electrical system.