Dimming and Brighting

[kelton]

This is more of a oddity than problem. When driving or when sitting at idle with headlight or heater on the power fluctuates causing the headlights to brighten then dim and the heater motor to speed up then slow down. must of the time everything is at the low end or the dim headlight stage, but randomly everything will kick up in speed and brightness for a few seconds then dim back down? Any ideas what this might be? sounds like something is failing and I would like to replace it before it goes.

[71highboy]

voltage regulator ?

[Thunderfoot]

that is a common sign of the Voltage Regulator going bad, or a bad connection inside the alternator.