Over the two years or so I've had my 81H I've had many of the usual charging-system problems: no-good alternator; funky brushes; questionable rectifier/regulator performance. I got the system in correct working order relatively easily, but the process left me with lingering anxieties regarding my bike's electrical prowess. Would I reach my destination? Would I make it home? Was that last miss a speck of spooge in the gas, or the first sign of an incipient toasted battery? Was the headlight really getting gradually dimmer the longer we rode, or was I just getting really tired?
Well, there was an obvious solution, and inspired by list-member and fellow granite-stater Pete Venne , who showed me the way, I decided to pursue it: A voltmeter.
I found the cheapest ($25) 2-wire voltmeter I could locate, which turned out to be a miniature LCD unit (Lascar Electronics part no. Lascar EMV1200) from Allied Electronics, on the web. Here's where you can find them: http://www.alliedelec.com/ It mounts with a single threaded post, carrying the wires, to 5/16th-inch hole and its obverse is perfectly flat otherwise.
This is a really simple meter: a red wire and a black wire; even I could figure it out. I decided to mount it over the idiot-light cluster between the gauges on the Specials, in place of the "Headlight Warning Light" (I'm pretty sure I can tell when the headlight goes out on my own). Connection couldn't have been simpler: I soldered the meter's wires to the wire-loop contacts of a burned-out bulb, and simply jumpered the HWL's hot lead to the plus side of the ignition switch inside the headlight. (Ever the lazy guy, I did this by using a paper clip with a piece of heat-shrink insulation, jamming 1/16th-inch or so of bare end into wire-side of the appropriate connector-blocks. This also obviated the need to cut or splice any wires.)
The meter lights whenever the ignition is turned on, and it works great, other than the fact that you can't read it at night---but an LED meter like Pete's would have cost almost twice as much. The bike produces a studly 14.4 to 14.8 volts at any revs above 2K or so---despite the fact that the alternator only measures about 4.2 ohms, well below spec. (It was free, so who's bitchin'? The one it replaced measured about 1 ohm.)
In retrospect, I'm not altogether happy with the mounting location---but now I've got a hole in my idiot-light bezel. Inside the tack, below the needle would be really cool, but hey, let's be reasonable. If or when I come up with something better, I'll put it up here.
Oh yeah: feel free to email me with any questions (or offers of free bikes!).