1974 commando not charging

From the reading I have done, the alternator output should be at least 9v AC.
I figured 17v was more than acceptable.

and I don't really wanna open the primary!

roqueweiler said:

From the reading I have done, the alternator output should be at least 9v AC.
I figured 17v was more than acceptable.

Click to expand...

9 VAC with a 1 ohm load, equivalent to 9 amps of current. But unloaded it's normally about 25 VAC.

Before investing in Podtronics or other fancy 'lectronics, I would go to the local Radio Shack and get a standard "bridge" rectifier - p/n 276-1146 http://www.radioshack.com/product/index ... Id=2062584 (picture doesn't show the terminal side). I had one of those on my '74 for 25 years. It will mount in the same spot as the factory Lucas part.

If the DC output comes back and the battery charges at 3000 rpm with lights on, you're GTG. If not, you'll need to investigate inside the primary. The magnetic rotor is what usually "wears out".

Besides, ~every~ Commando owner needs to be familiar with the primary workings...

9 VAC can not make 14 VDC...not possable without a voltage multiplier circuit. Where did you get your stator output information from?

I am running into this same problem now that the harness is back on .I will be playing with this tonight after work. Thanks

Hey Dave and all,

The alternator is pushing 17 VAC unloaded. I was gonna test loaded today and run some other tests but it was too nice so I rode my other bike to Mission instead!!

I have pretty much decided to replace everything with the triple phase Sparx high output unit from Brit cycle supply in Nova Scotia.

I have learned however from the PO that the PPO installed a higher output interpol alternator

Any thoughts?

The 3 phase alternator will output more at lows revs than any of the single phase alternators including the high output ones, at higher revs the difference is much less, as I used my Commando for commuting in a city with 30/40 mph limits I went for the 3 phase, only other way to stop needing nightly battery charges was to use a lower gear or have daily speeding ticket .