A look at this one http://tinyurl.com/2mkqz
The light only comes on if the voltage drops below, I think, 11.5. I personally found the constant on units annoying. The unit is tiny, about the diameter of a quarter. Simple hookup as well. I'm not sure if the speedo is accessible without damaging the whole unit. I'm planning on mounting this light through the warning light/ ignition housing. You only need to drill a 1/4" hole, and tuck the wiring underneath the housing for protection
- Check the charging system voltage at 4000-5000rpm. It should be 14 > volts or more. Remove the right side cover, and find 2 wires with > nothing connected to them, the Black/Yellow is ground (frame), the > White/Blue is battery + voltage. Check the volt meter on a running car > battery first, looking for the same approximate reading on both. If > voltage is only 12.x it could be very costly to have repaired. Could > be $130 and 20 minutes or $$$ and weeks out of service.
- Yes, good point. Comparing your car running with your hand held voltmeter, and then checking your bike at the battery terminals running WILL give you quite a good idea of what's happening with your electrical system. Very good baseline. Will also help you calibrate a voltmeter you are looking to install on the bike. Installed voltmeters on the bike HELP you monitor the electrics, but with resistance in the wires, connectings, relay or not used, etc. ; you only get a RELATIVE indication of what's up. For instance, my bar mounted cheapish digital voltmeter wired up through a relay with crimp on connections using 18 gauge wire reads .3-.5 volts low than actual. I don't get upset when it reads 13.2 volts after a lot of in town running around. I know what MY bike should read under WHAT conditions and can monitor it that way. An hour after pure freeway riding at 4500 rpm, sure, it reads 14 volts and the battery is fully charged. But at a stoplight, in hot weather for awhile fan running, holding in the brake, with the Knifemaker lightbar turned on, the voltmeter will read 11.5 volts till I'm on my way again.
My voltmeter fluctuates constantly while riding..anywhere from 14.2 to 14.8 volts...If the rpms are held (as best as possible) to one level, say 5000 rpms...the fluctuation is about +- 0.2 volts. The meter I have has no "buffer" to even these readings out..and I suspect that these small fluctuations are normal. When I turn the bike off the reading slowly drops to 12.8 volts and stays there. The biggest variance seems to be when starting the bike..where the readings go from 11.2 volts to 14.9..but once the bike is warmed up the bracket is closer to +- 0.3 volts. Given all the info I have on the way the bike produces electrical power and the sensitivity of my voltmeter, I'd say these slight changing diffrences are normal for this system...as holding an exact rpm level and load on a running engine are fairly impossible unless the bike is strapped to a dyno. KM