Charging System Troubleshooting

[Mjolinar]

Is there a guide posted here somewhere that has step by step troubleshooting for the charging system? I have tried the search but I'm either doing it wrong or there's just not anything posted already. I'd appreciate any help.

Thanks

[Barry]

You can tell a lot just by measuring the charging voltage and this has certainly been discussed many times but maybe you won't find everything about the charging system covered in one thread.


Here's a link to Robin Frankhams write up on fault tracing in the charging system and diode board.

http://www.frankhams.freeserve.co.uk/bike_index.htm

and a good description of how the whole system functions

http://www.buchanan1.net/charge.shtml

and another on charging system maintenance

http://www.horizonsunlimited.com/tech/R-charging-maintenance

[Bob_Roller]

What problem(s) are you troubleshooting in the system ?

[Rob Valdez 79 R65]

The only book you'll need to understand and administer to your Boxer charging needs. No Airhead owner should be without this classic! Classic Boxer Charging includes color graphics, explicit photos, and charging system wiring diagrams for every Airhead Boxer model 1970- 1995 (in color!). Keep your Boxer thump, thump, thumping along! Recently updated with all the latest wisdom.

http://www.motoelekt.com/goodstuff.htm

It is written in 'Merican English, but it is supposed to be one of the best books around (I've yet to buy one).

[montmil]

... It is written in 'Merican English, but it is supposed to be one of the best books around (I've yet to buy one).

Go ahead and treat yourself, Rob. I bought one last year. The trouble shooting steps are worth the price of admission. [smiley=thumbup.gif]

Monte

[Mjolinar]

Fantastic guys! Just what I was looking for. At the moment my bike is running fine. Have the red generator light on for just a minute or so when starting up in the morning but that could be a sign of the system starting to go out. A local here in Phoenix was looking for someone to fix his charging system on a '75 R75? and I offered to help out. I wanted some literature on the whole system because it's always better to be a bit familiar before tearing into something.

Thanks to all!

Merry Christmas!

[Rob Valdez 79 R65]

Have the red generator light on for just a minute or so when starting up in the morning but that could be a sign of the system starting to go out.

Nope - that is normal.  Well - 15-30 seconds would be normal.  Mine usually goes out as soon as I rev the engine a bit.

Monte, I am waiting to land this job I have been offered (but still waiting on the background check stuff) before I spend any money on the bike.

[Bob_Roller]

Just curious what is the issue is with the R75's charging system ?

[Mjolinar]

Red light all the time and battery dead after a couple of days.

[montmil]

Red light all the time and battery dead after a couple of days.

If the charge lamp is still burning above 1500 rpm, check the voltage regulator. Do this by disconnecting the regulator from its plug. Use a short 12-14 ga jumper wire with male spades on the ends to connect the blue and black wires in the wire harness. Start up engine and see if the charge light goes out. If it does go out, the regulator is faulty.

After that, check the following items are in order of their probability of causing charging problems:

     Rotor
     Diode Board
     Loose or corroded or broken connections
     Stator
     Brushes & springs
     Battery

Thank you, Rick Jones of Motorrad Elektrik, and your Airhead Diagnostic Flow Chart [smiley=beer.gif]

Monte

[Bob_Roller]

That pretty much narrows it down to anything, except an open circuit in the rotor .

[tvrla]

The most common cause for the charge light staying on is a bad rotor.

The way to test is, with ignition on and charge light illuminated, short across the two slip rings. Light goes out, rotor has open windings.

If no joy, next would be brushes. Ground the DF terminal at the Stator. If light goes out, it's the brushes.

I'm sure one of those two will flush out the source. If not, then the next most likely suspect would be the diode board.

[Bob_Roller]

Did you ever find the charging system problem(s) with the R75 ?