Intermittent Headlight Problem

[n4mwd]

I don't ride at night that much so I don't know how long this has been going on, but I noticed while riding last night that the headlight was intermittently going dim - about half intensity. Then it would come back to full intensity. I switched to high bean and had the same thing happening. Eventually, as the ride progressed, it stayed the normal intensity.

Anyone know if this is a common problem with the pregen? The bike has about 20K miles on it.

Does the headlight relay fail in this manner?

I did not notice any dimming of the dash or turn signal lights. In fact, when the headlights were in their dim mode, the turn signals were actually brighter.

[alex.s]

Battery ground

[n4mwd]

Thanks, I will take a closer look at it tonight when it gets dark. This afternoon I couldn't tell anything was wrong.

[n4mwd]

I found the problem. It was a faulty voltage regulator AND a bad battery. The voltage regulator was cutting off and on causing the voltage to go from 14V to 12V causing a noticeable difference in brightness. Not sure if the battery went bad because of the regulator or caused the regulator to go bad. In either case, I changed out both.

Note: The battery was cranking down to 6-7V which is too low for the igniter circuit to work properly. This was also causing hard starts. With the new battery and regulator, just a tap on the starter button and its running.