I need some input on this one. Bike is a 2016 Road Glide Ultra with 7K miles. Coming back from a weekend trip after riding about 150 miles I noticed my volt meter was fluctuating from 14 to 15 volts. It seemed to be bouncing off the red zone. I have a Power Vision tuner and I had the system voltage on the gauge section. On the Power Vision it was dropping down to 14.1 and was able to read as high as 14.8 volts. I was on the interstate running steady at 3000 RPM in 6th gear.

Decided to add some load to the system and turned on the high beams. Voltage on the gauge and the power vision went to a solid 14.3 volts. The voltage stayed there for the rest of the trip. If I turned off the high beams off it immediately went back to bouncing between 14 and 15 volts.

I recently put a new YUUSA battery in it so yesterday I swapped to the old weaker battery. Started it up and brought it up to 2500 to 3000 RPM. Same fluctuation started and turning on the high beams brought it back to normal (14.3 V) and steady. I cleaned the battery connections when I changed the battery.

I am thinking voltage regulator but would like some input before I start throwing money at it.

Any input is appreciated.

 

harley volt gauges are notorious for being inaccurate. i would check with a hand held meter first and go from there.

 

probably normal. the regulator is clamped at 14.3 volts but there is skew factor so it could swing within tolerance. some regulators have diff clamping zener values but function the same.
in reality, the battery when charged, drops out of the equation and the machine runs off the alternator, the battery tagging along in case there is a short fall. that said, as the regulator switches in/out the battery there will be fluctuations and when you load the system, the extra load stabilizes the system as current draw nears closer to steady state value.

 

Great explanation! I thought that might be the case the fluctuations were the charging system kicking in and out. The voltage I was seeing was all within the limits it was just the fluctuations that were a concern.

I will keep an eye on and and not worry about the fluctuations as long as they are within the 14.0 to 15.0 range.

Thanks!