Misc: Charging Systems Nippon Denso Alternator

[tractorman414]

Hi, I fitted a replacement Nippon Denso Alternator recently, admittedly I dismantled it to cut a keyway for a keyed pulley.
Whilst riding, the ammeter sometimes shows a discharge. If I flick the ignition quickly off then on (ignition also switches the exciter connection to the alternator) then it starts charging again. Any clue what's going on here. In the absents of a simple answer I will replace the inbuilt control unit
Bernard.

 

[timetraveller]

Just checking here as some people confuse different alternators. Is this one of the 40 amp alternators I now fit to my alternator kits ( know it is not one of my kits)? Also is it a Nippon Denso or a Denso?

 

[tractorman414]

thanks timetraveller. Was not aware of the distinction, Yes the label is "Denso" only, ref 101211 1032, .sold a "compact 3kg race alternator 40a 2 pin."

 

[Pete Appleton]

How is it wired up? Is the plug like the one shown below? If it is then you can ignore the 'P' wire but the 'IG' needs to be a switched 12V feed for voltage sensing and the 'L' is where you ground your charging light.

 

[tractorman414]

Hi Peter. It's a 2 pin connection, one blade vertical other blade horizontal
ignition and warning light
Bernard

 

[Pete Appleton]

Sounds like you have it right. You say 'a replacement alternator' does that imply that a previous one has failed? They are usually very reliable so I would suspect something on the bike.
The ammeter is a source of worry to the rider, I prefer a Voltmeter and so long as it stays above 13 & a bit I am happy.

 

[Vincent Brake]

Maybe EMC??

Build a coil in??
Available at trispark