I've got a 2002 Heritage, EFI. Occasionally, the lights get very bright for a few seconds, then they return to normal. It's not at all predictable--it can happen at any time. The frequency is probably about once per every hour of riding.

I figured that the problem was probably a bad ground at the regulator or at the battery. I took all of the ground connections apart, and cleaned them up like new. The problem still occurs with the same frequency.

I'm now thinking that the problem is a bad regulator, which malfunctions intermittently. At idle, the voltage at the battery is good (around 14.3 volts). Have any of you had a regulator to behave in this way?

Thanks,
Dan

 

I had a voltage regulator go bad a couple of months ago on the road. Turns out it was overcharging the battery. Luckily I had a loose terminal and every time the regulator would overcharge my bike would momentarily quit...no power, electrics, etc....dead at 70 mph. Then a couple of seconds later, the power would return and I could start the bike by letting the clutch out. A dealer can run a test on the regulator and tell you if it's bad. It costs around $170 (dealer cost/labor) to replace it.