To all the motolights users out there.....
I had the dealer install mine and hook it up to the AUX switch on my Ultra. They work fine....except, when I come to a stop and the bike is at idle....the voltage gauge drops to 12 or just slightly below. I had the dealer check it and they said my alternator was "just" barely at spec, so they replaced it under warranty. (nice!). However, the volt meter reads the same after the new alternator was installed. The dealer says I should not worry because the gauge isn't very accurate. Easy for them to say.....
I fear I'm getting a drain on the battery by using the motolights. I do keep the bike on a battery tender anytime it is not running.
Does anyone else have this same experience with your volt meter? What does yours read when you have the lights on and are stopped at idle?
Thanks for your feedback...I may be worrying about nothing, but I'd like other real world feedback.
Thanks,
Dash
aka Mike
Did your dealership offer to share any real information, such as total current draw, net charge/discharge at idle with all accessories on, etc.? Or did they just leave it at "Don't worry about it"?
They did tell you the truth about the stock volt guage, it's a POS that's about as useful as the air temp gauge. If you happen to have a multimeter, use the voltmeter to check voltage at the battery as tennisman suggested. Since a fully charged battery will show an open circuit voltage of approximately 12.8 V, you would expect to see at least 12.8 to 13.0 at idle with a fully charged battery in the bike. Run the rpm's up until the voltage stabilizes at the regulator setting, and you should see 14.5 +/- .2 volts. While doing this, compare the real voltmeter readings to the poor excuse for a gauge on the bike for a real chuckle.
The best way to determine if you have sufficient alternator output for the total load of your bike plus accessories is through proper current output and current draw tests. Any decent shop can do those tests for you. I believe the specs call for testing at 3000 rpm, but you could also ask them to perform the test at idle to see how much deficit, if any, you have.
Jerry