Hello good people

I have a 1970 cutlass w31 with a 350 rocket motor. I’m having some gen light issues. I’ve replaced the alternator, alternator belt, battery, volt regulator, (Brand new) and the light still will not go away. It only glows when I push the pedal. When I raise the rpms it goes off. While I sitting it will go on and off and when I’m driving with out pressing the gas (coasting), it will come on...any ideas of what I should do or where my issue is coming from?

 

did you check the voltage output of the alternator?

 

What’s the charging system voltage, with and without the charge lamp on?

The charging system warning light is pretty simple. You have power on one side of the charge lamp provided by the gauges fuse. With the engine running, the regulator supplies power to the other side of the charge lamp on the brown wire. With the engine running, and a functional charging system, the light can’t illuminate with power on both side of the lamp. If the charging system fails, the regulator will provide a ground on the brown wire, causing the charge lamp to come on.


With the light on, unplug the regulator. If the light goes out, then the regulator is providing the ground for the charge lamp. If the light is still on, then you have something else provide a ground to the light. Examine the brown wire, make sure the insulation is good and the wire isn’t grounding out somewhere.


If everything looks good, replace the regulator. Just because it’s new, doesn’t mean it’s good. Was the regulator replaced because of this issue, or another concern?