Bike charging system

At the end of last year, my Honda Shadow VT1100C stranded me on the return
trip from NY to FL, requiring me to truck it home & place it in storage for
the winter.

I dragged it out and am trying to troubleshoot teh electrical problem, and
remember all the details of the failure.

Original problem - would spin over, but not start until battery died (in teh
rain of course). I found a loose wire on the neg post of the battery, but
buy then the battery was dead. Bike would start with a jump, but only ran a
few miles before it quit (headlight dimmed and no more ignition), and I had
to coast into a driveway (did I mention the rain - it was the end of the
hurricane season).

So I bought a new battery and had it charged at a local (where I was) bike
shop who did some troubleshooting. I was told the bikes charging system was
not charging the battery. They did some measurements, tried a used voltage
regulator (no change), and told me I needed a new stator ($350+), plus a
weekend wait in the middle of nowhere. We opted to rent a truck & drive home
as the $$ were daunting.

So I am here with the bike apart - I trickled the new battery all winter &
it appears good. I got the bike started & it runs fine. I have the
maintenance manual for the bike & performed the resistance checks on the
stator per its recommendations - all 3 leads measure within the 0.3-0.5 ohms
with no shorts to ground.

So I am stumped. What voltage should I be measuring at the battery when the
bike is running?
When off and at rest the battery is now reading about 12.5VDC.
When running (idle) it reads about 12.25V.

Maybe I should drive it & measure the batt voltage a few times?

Any suggestions?

Thanks for the help!

SpiderG

 

Try this:
https://www.electrosport.com/electrosport_fault_finding.html
PQ

 

Put test leads on battery and run engine at 4000 rpm's The meter should read
14.5 volts if it is not, it's time for a stator.
Bob H.

 

The loose wire may be enough to explain the original problem, although I
find it hard to believe that that shop would try to convince an
out-of-towner that he needed an expensive repair when he didn't.

My bike has to go at least 2200 RPM in order for the battery to get any
charge. Slower than that, the lights eat up the power produced by the
generator. Your voltage should be higher at 4K than it is when the
engine is off.

Okay, hopefully it has stopped raining by now. Get some good rain gear
if you don't have any. Then do the following:

Make sure you have money in your wallet, and that your cell phone is
charged, and that you are well fed and watered and rested. Gather up
your best biker friends. Then start the bike and drive it into the
street and then back into the driveway. Shut it down, get off, and talk
it over with your friends. You may want to measure the voltage. If you
are still feeling fine, repeat the operation, this time driving a
hundred yards before returning. Then take it around the block, then
twice around the block, then four times. Then drive it a mile away,
then two miles, then four miles. If at any point you notice a
deterioration in performance or battery condition, have the motorycycle
checked by one or more experts. Otherwise continue increasing the
lengths of your excursions until you have made a round trip to a distant
point such as New York or California.

 

Hmmm ... that link doesn't work for me.

 

Just try this and go to the fault finding diagram under Tech Support.
PQ
https://www.electrosport.com/

 

Put test leads on battery and run engine at 4000 rpm's The meter should
read
14.5 volts if it is not, it's time for a stator.
Bob H.

Not necessarily.
Low voltage is not always just a stator problem.
In bikes with a rectifier/regulator unit as one, if the regulator circuit
goes, you get low voltage charging to the battery and the stator tests out
fine. I have such a beast in my driveway now - charged new battery reads
12.50v, with bike running reads 12.55 and starts dropping. Stator tests over
60VAC at 4K rpm on all 3 leads and the resistance is within spec.
Rectifier circuit is good (diode and resistance test) but the regulator is
shot, (resistance test with a meter and shop manual).
PQ

 

It works for me now. Earlier I got messages saying the connection was
refused.

 

worked for me.

Ben

Ben

http://autos.groups.yahoo.com/group/rockland_mc_riders

 

That is a great site!
Thanks PQ

SpiderG

 

I have found this connector & pulled it apart & together a few times now.
The bike maintenance manual said to measure between 0.3 & 0.5 Ohms between
windings (measured OK), and open between each winding & ground. Now I used a
pretty good DMM, and set it to read relative change in resistance, after
compensating for the meter lead resistance, so I am pretty confident in my
readings.

Thanks for taking the time to reply!
-SpiderG