Checking The Charging System

I have not verified that the charging system on my 74 850 Commando is working.
Just got the bike running/riding so I figured it was a good idea to find out if it is charging the battery as it should.

What is the best way to test things?

Jaguar
Al Osborn (UK Norton Owners Club Electrical Specialist) has various electrical tests on his website which I have been using to refurbish the electrics on my 1972 Roadster to good effect.
You'll need access to a multimeter for the Full Output Test shown in the following Broken link removed.
Should give the assurance needed. Hope this helps.
Andy

That should do the trick!

Thanks

I just checked my alternator output (found the system wasn't charging due to a bad bullet connection) The MkIII manual says to wire a 1-ohm resistor in parallel to your multimeter leads, which I did and got a good reading. But the resistor was too small in wattage and began to heat up and smoke during the test. So if you do this test as prescribed, make sure you have a resistor that can handle the 180-watt output (15 amps@12V) of the MkIII alternator.


My final check was to fully charge the battery, do about 30 miles of varying condition riding and then see how long it took to charge up afterwards. As soon as I hooked the charger up, the green light came on, telling me the battery was already fully charged by the system, so fixing the bad connection was all that was required.

Danno said:

My final check was to fully charge the battery, do about 30 miles of varying condition riding and then see how long it took to charge up afterwards. As soon as I hooked the charger up, the green light came on, telling me the battery was already fully charged by the system, so fixing the bad connection was all that was required.

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That is what I do - no meters / resistors / electrical knowledge needed.
If the trickle charger is on more than a few minutes after a ride, alternator is not doing its job.

I also have a Gammatronix LED charge indicator which lets me know if the battery is charging or discharging while I ride.

I have not verified that the charging system on my 74 850 Commando is working.

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very simple, fast, and easy way to check your charging system in your garage

get out your inexpensive voltmeter and hook the leads up to your battery

start the bike and have an assistant stare at the volt meter while motor is idling at 1000 rpm = no reading at all, then reverse the meter's leads to the batt terminals as you had them backwards

turn the throttle so the motor is turning faster around 2000 rpm, if your assistant exclaims that the volt meter is now showing a higher reading-you are charging!

and if the volt meter reads the same as at idle then you are not charging and should not trust going for a ride until you find out and fix what the problem is

this could take all of 5 minutes

If the headlight gets a bit brighter as you rev up off idle, it's charging.

Install one of these and never be in the dark again:

http://www.sparkbright.co.uk/sparkright ... onitor.php

I put one of those cheap ebay digital voltmeters on mine. Learn from my error and fuse it!
They wont work in the bright sun so put a shade on them. You can just shade it with your hand.
Perhaps Ill go to a good analogue one in the future.
Lots of people think gauges are waste of money, distracting, overkill etc but I find it better to
know than not know.