Just had an issue on my bike, thought I'd pass it along, could help someone out. A coupla days ago, I noticed my headlight get dimmer when I kicked on the driving lights. Rut roh, voltage drop. They both run through the aux panel. When I arrived home, I grabbed my trusty $11 multi meter and checked things out. With all lights fired, I was losing about 1 volt from the battery to the panel trip relay, and another 1/2 volt through the eight year old relay. I touched the relay, somewhat warm, I touched the battery terminals(the aux panel power is direct wired to the battery, through a relay tripped by the Jbox blue(I think) wire), positive was hot. Replaced the relay, cleaned up the connections, all is good.
The battery has been in for about five years, I guess it was due for a terminal clean. There was no funk around the terminals, I guess things just got oxidized in there.