Charging System Gurus... HELP!

OK, the Achilles Heel strikes again!

Swapped out my 4th gen. OEM R/R after charging failure a couple years back with a finned unit relocated in the air stream under the lower triple clamp where the stock horn goes.

Today another failure... first my low beams wouldn't light then the highs as well... checked light sockets with a tester, both hi/lo showed live. All other lighting works fine.

Bike conked out, battery drained wouldn't spin the motor. Got a push, started up then quit again... stranded in a thunderstorm with pea sized hail, just lovely!

What do these symptoms sound like? Stator maybe?

 

this sounds like either bad groung, baked/burnt connectors or the r/r. look for and make sure you have a good negitve frame connection both at the battery and at the other frame grounding locations. if you think its the stator then you can test it but you will need some equipment(stuff from the parts bin can be made to work). simply using a multimeter and measuing each of the three stator fields will give you a good indication if the stator is really toast, but it may show good at low voltages (meter=1-9v on resistance). Keep in mind the stator puts out +/- 70vac at 5000rpm(no load voltage) the r/r puts a load on the stator and drops it to a managable 24vac and converts it to aprox 14.2vdc. if you have anything from 13.6 to 14.8vdc at the batt when engine is at 5000rpm then I would say the charging system works fine.

Things to look at:
bad grounds, your lights can act as a source to ground if a bad ground exists.
melted relays, it looks good on the outside but looks like cheese left in the sun on the inside.
bad connectors, these can range from melted to "looks like new but i get a shock when i touch it"
bad battery, some batteries test fine, but are bad. A proper test requires you to either do a specific gravity test ( can not do this on sealed batteries) or do a loaded voltage drop test (requires large resistors of known values at 1% accuracy. take it to a shop you trust and have them put it on a "load meter" to determine the battery health, this takes 5mins and costs 10$ usually.

the R/R has diodes in it that can just die, since the stator puts out 3-phase ac, if you loose one diode its not a problem but loosing two may act as a resistance across the battery and drain your battery. if the battery can not last over night then on a fresh charge unplug the r/r from the harness and let it sit, if the problem goes away then change r/r, if not you now know its either wiring or a relay or the reverse current diodes for your turn signals.

hope this helps as electrical can make some weird things happen and not always the same twice.

 

@ mello dude...those are the best instructions ever. You hit the nail on the head. Nice job.:hss:

If you want a r/r test follow these instructions:

 

Adding already great tips.

1.Change your r/r to Mosfet style unit.Runs cooler and rarely breaks.I installed Yamaha R1 unit.Lots of them on ebay 75-100 range.
2. Connect direct to battery from R/R with heavier wires.Solder and heat shrink wrap.
3.Solder direct stator wires to r/r by passing connector which is mostly the main failure point.

You'll find your bike runs smoother and better.

Mosfet style R/R are a must.No need for flimsy PC fans etc.They run cooler and you can actually put your hand on it.Technology is different.
Google it and read about it.I like Yamaha personally 04 or newer.Mine has beefy fins as well.
Lot of guys bought Ricks units.Mine failed and I am skeptical of Ricks products after seeing mediocre insulation on his stators.
Buy japan made Mosfet unit!