voltage gauge

[johnnnyo]

Anyone have any suggestions on where to tap in for a key on only power source for a voltage gauge I'm going to install on a 2002 Yamaha V-Star Classic? I want to monitor my charging system now that I changed my regulator/rectifier. Thanks.

[WintrSol]

With many metric bikes, power is present in the headlamp bowl; usually one wire for the running lights, another for the headlamp. Ground is usually in there, too. Not the most accurate measurement of voltage, because of loss in the wire to that point, but often the most convenient. If you use the running lamp power, the loss is lower than for the headlamp source.

[johnnnyo]

Originally Posted by WintrSol

With many metric bikes, power is present in the headlamp bowl; usually one wire for the running lights, another for the headlamp. Ground is usually in there, too. Not the most accurate measurement of voltage, because of loss in the wire to that point, but often the most convenient. If you use the running lamp power, the loss is lower than for the headlamp source.

Thanks WintrSol. Your right it would be convenient there but I kinda want to get a pretty accurate reading since I'm testing a new regulator with a Volt gauge. About how much voltage do you think is lost at the running lamps?

[WintrSol]

Drop varies by gauge, length of wire and number of lamps on the line, but I would expect 1/4-1/2 volt on average. If you want really accurate readings, run the wires direct to the battery, with either a switch or relay driven by the running lamp circuit to turn it on.