I want to add an amp gauge to my 71 Bonnie. On my BSA A10 all regulated power runs through the gauge before going to the lights and battery. Is this necessary or can I simply run a wire from the podtronics unit to the gauge and back to the battery? Will it show power consumption from lights ect without the lighting wiring passing thru it? Thanks
1960 BSA A10 2007 Suzuki Bandit 1957 A10 (Used to be a Triumph here) 71 Norton Commando
You could do what Triumph did before the year of your bike.
If you study a '71 wiring diagram, you'll see the Brown/Blue cable connects battery, rectifier, Zener and ignition key switch.
Otoh, a '70 or earlier wiring diagram shows that Brown/Blue only connected the battery to one side of the ammeter; rectifier, Zener and ignition key switch were connected by Brown/White to the other side of the ammeter.
You've replaced rectifier and Zener with a Podtronics but the principles of a pre-'71 wiring diagram hold true - connect the battery to one side of the ammeter and the Podtronics output to the other side (and the ignition key switch); then the ammeter will show you draw from and charge into the battery.
Originally Posted By: MikeG
if I ran a seperate wire from the regulator to the gauge and back to the battery all it would read is alternator output, any other load I put on the system would not show?
No. As Craig has indicated, Amps are the units of electrical charge past a given point. So, if all you want to read is alternator output, the ammeter must go between the Podtronics DC output and the rest of the harness. In practice, this means you must run a cable from the Podtronics DC output to one side of the ammeter, then another cable from the other side of the ammeter back to where the harness originally connected to the Podtronics DC output.
Then what sort of gauge do you have in mind? Ime, the commonest ammeters for vehicle mounting tend to be around 2"/50mm dia. with about a 90-degree needle sweep, central zero so about 45 degrees either side to indicate the current direction. Otoh, if you want to measure just alternator/reg.-rect. output, you need a scale with needle on one side, with a much greater angular sweep, and/or a larger gauge diameter, to be able to see any detail on the move?
Last edited by Stuart; 01/04/122:29 am. Reason: Additional info.
On my BSA A10 all regulated power runs through the gauge before going to the lights and battery.
No.The alternator output is connected to ignition switch and light switches,without having to go through the ammeter.
Only the battery and the horn are connected to the other side of the ammeter.
The battery only gets charged through the ammeter if the lights etc already have their share. The battery only discharges through the ammeter if the alternator output isn't enough to run lights etc.
When the ammeter burns out,you only lose assistance from the battery (but the horn might still work from the battery).If you have a 2MC capacitor,you might not even notice until you slow down.Without the capacitor,the ignition timing will be out of phase with the alternator and you will notice;the bike might not run above idle without misfire.
You can run 6" of wire between the ammeter terminals for insurance.The ammeter will read about 1/2 as much,but it will still show if you have charge or discharge.The bike won't stop if the ammeter burns out.There's 1/2 as much current trying to burn it out.
If you don't like that idea,the voltmeter is good.Nothing stops if the voltmeter fails.