HELP: Electrical Problem

I'm having a difficult to track down electrical problem on my 1990 ZX-6.
Here's what happened the other day:

- didnt ride for about 1 week
- went out, bike started fine, rode for about 5 mins.
- bike started dying like it was running out of gas, cant remember if
power/lights/etc. started flickering

- pulled over as bike died
- tried to restart
- battery was acting like it was dead (motor would barely turn over)
- push started it no problem
- drove straight home no problem except that headlight went out

- out 2 days later to garage
- bike wont start....battery seems weak, barely turns bike over
- hooked up to 500mA slow charger for 1hr.
- bike starts fine and now headlight works again! MAGIC!

At this point, I dunno if battery is being overcharged or undercharged or
just cant hold a charge. So here's what I tried:

- checked charging system by running engine to 4000rpm
--> 14.5V on voltmeter
- checked alternator wires for continuity
--> 3 wires and full continuity between them
- tried to check rectifier/regulator according to manual
--> rectifier readings were all backwards from manual
--> ie/ when it was supposed to read inifinty it had a reading
and when it was supposed to have a reading it read infinity
--> I am not much a mechanic so I am assuming I got something
backwards or the manual is backwards so guessing this part is
working
--> regulator....where the heck do I get 3 12V batteries to test
this?? should I bother??

Note that over the winter I charged the battery with a 2A car trickle
charger for no more than 6hrs at a time 2X a month so not sure if I damaged
the battery. Hate to buy another new one....it seems like I buy one every
spring...without knowing part of the electrical system is not damaging the
battery.

If anyone has suggestions or tips they are greatly appreciated.

thnx,
Steve

 

(Kaybearjr) wrote in

I should have mentioned it is a digital multimeter...I will try this
suggestion too.

this was fine

digital multimeter...but maybe Haynes was using analog so they got it
backwards ??

looked fine here

not too sure on this...the charger says 2A charger and there is only one
indicator on it...a light that comes on....so I have to assume it was 2A.

i'll look into this but not sure I can get one for my bike...what brand
do you recommend?

great! thnx a lot for the help.

Steve

 

Sounds good, but where'd you measure it? Battery, Regulator, somewhere else?

That's odd. Does the meter have a diode test range? Best use that
if available. Most digitals do.

Could the meter leads be switched? Red in "common"?

You lost me here, how are three batteries used to test a regulator?

That's a lot of charging for a typical motorcycle battery, but if it started
the bike once the battery can't be too bad.

I'd urge you to try following the fault finding chart provided by Electrex:
http://www.electrexusa.com/electrex_fault_finding.html

bob

 

What's your battery reading with the engine at lower RPMs ?

Last time I went through this exercise, the alternator brushes
had reached their wear limits and while I was still getting
some charging, it had definitely dropped off at lower RPMs.

What's the battery voltage after you shut the bike down ?

If you've lost one cell on the battery, your charging
system may be able to bring it up to correct voltage, but
it'll drop off quickly when you shut down the engine. (At
14+ volts, this seems unlikely but not impossible)

Also, what kind of shape is your starter in ?

Might also be an intermittant short in the wiring, though
I'd expect this to blow fuses.

Not sure what to make of your reversed readings on the rectifier,
but if the battery voltage rises when you run the engine, then
I'd assume you had your leads reversed when you took the readings.

You might also lash up a voltmeter so you could see what's
happening as you're riding. This'd tell you if you were getting
big fluctuations in voltage or a slow steady drain.