Irratic Alternator gage on 69 Charger

[Danny]

Hi to all charger owners !!  Does anyone know what the alternator being erratic means on a 69 Charger RT when idle.
Please help!!!!!

[b5blue]

Most likely low Alt. idle output. Swinging back and forth? Start by checking ground wire/straps. 

[Danny]

What do you mean by ground wire strap  Can you show me a diagram  if possible Thanks

[K9COP]

Danny, the 'ground' or 'earth' wire or strap are points in the car's wiring harness where a wire is bolted or attached to the frame of the car. You have either positive from the battery, or ground from the chassis. Our cars are VERY sensitive to grounding/earthing problems, and the ALT gauge can burn out or even over heat and catch fire. I don't want to scare you unnecessarily, but you have to be aware of that issue with our cars. Does the ALT gauge go steady if you rev the car? Sounds like bad ground connection, or poor alternator output.

CS

[Danny]

Thank you very much for your information much appreciated

[Ghoste]

There is usually one going from the back of the engine to the firewall somewhere near the voltage regulator and there may be another from the negative terminal at the battery to the rad cradle.  Are you running other electric items when you note this like headlights and turn signals and maybe a big stereo?