Electrical question from an electridiot

Hi All. 1985 Kawasaki GPz900R. This bike has a totally inadequate light for
night riding (unless you ride 20kph in the city) so brilliantly (no pun
intended) I decided to add a set of driving lights. I bought a pair of 55w
halogen, (H-3 bulbs), running lights at the local surplus store and
installed them wired in with a relay and toggle switch. I should have
labeled the damn switch as it was identical to my fan switch and I
inadvertently left the lights on for an 80 kilometre daytime errand last
weekend. I didn't notice they were on till I pulled up behind a minivan. I
shut them off and thought nothing of it, and continued on my merry way till
the bike started to bog. Checked the usual, fuel was on, so switched to
reserve and finally it just died. While pulled over on the shoulder I
discovered I had no battery power left. Got a boost, made it about 20 km
back till it died again. Several boosts later I got it home and discovered
my alternator is no longer producing much juice, approx 8 volts at the
battery while running, bike stops if the battery is disconnected. Was the
draw from these 2 running lights (coupled with my fan being run all the time
to keep this bike running cool enough in 26 degree heat) too much for my
stock alternator? Or was it on its way out already and this simply pushed it
over the edge? I really need additional lighting to ride this bike at night,
so any suggestions on how to achieve it without frying anymore expensive and
nearly unobtainium 21 year old parts?

thanks all !

Tom B

 

The lights weren't bad on the 1984 A1 GPZ900R I had a few years ago.
Have you checked that the battery is OK, it's more likely to be that
than the alternator that is causing the problem. It's not a good idea
to disconnect the battery while the engine is running, I think it can
damage the rectifier.

Leon

 

Yes, you are an amateur when it comes to electrical system design.
Aren't we all?

Don't feel bad, we all get caught out by our ass-umptions about how
much electrical
equipment we can add to our motorbikes.

Basically, a motorcycle is a gasoline powered flashlight that you can
ride on. I hardly ever ride at night anyway, but I once added two
Carello driving lights, skillfully aimed to illuminate the road
regardless of which way I leaned as I dashed about in a sporting
manner.

Of course the extra load on the electrical system reduced the amount of
power available for charging the battery, and riding the motorbike
through the desert in 100 degree heat was bad for the battery too.

But, more subtle things were happening besides the discharging,
dehydrating, and sulfating of the poor battery.

The Big Four Japanese motorbike manufacturers do not make their own
electrical equipment. They outsource that stuff from a few
manufacturers of alternators and
regulators, and what fits one machine will work on another machine if
the electrical system designer can figure out what kind of connector to
use to plug in the selected parts.

Of course the electrical system on a motorbike has a myriad of small
plastic connectors, and the connectors are there to make it possible
for a *mechanic* to quickly change parts and still make money.

It would be far, far better, if every electrical bit had a soldered-on
terminal (the Brits called them "ring tongue tags" on a business jet I
once worked on). It might take five minutes longer to hook up the
terminals, and the mechanic would have to *pay attention* to what he
was doing, but the terminals would make far better connections than the
damned plastic plugs that Japan Inc. uses on all of its motorbikes.

The connectors on an alternator are often bullet and socket type
terminals like Honda used back in the early 1960's. But the connector
on the regulator will usually be a square plastic plug.

How do you connect the alternator to the regulator, if the connections
supplied by the
various manufacturers are so different?

You have to add extra wiring and short pigtail wire harnesses to plug
the parts together. Every extra electrical connector generates more
heat, and this causes plugs and bullet connectors to get so hot they
melt plastic, the turn their insulating sleeves black from heat.

So, besides replacing your poor dead, dehydrated, sulfated battery, you
will need to inspect the electrical connections all the way from the
alternator to the regulator and all the way through the system.

The bullet type alternator connectors on my Suzuki melted after riding
at night using the extra lights. The extra plastic connectors and the
pigtail harness melted. A wire that went all the way to the headlight
bucket to a headlight switch that foreign models used (but my machine
didn't have) melted.

So, check all your electrical connections for overheating, turning
black, melting, etc., before you start buying alternators and
regulators. The battery is probably toast, though.

 

Old dirt bikes were like that, but street bikes use DC to run the
lights.

That's still very true. Motorcycles are like gasoline-powered
flashlights.

There is enough electrical power to charge the battery and run the
lights and operate
some accessories, but the owner needs to realize that all add-on
accessories have to go through three bottlenecks, which are:

1) the connector where the alternator feeds the
rectifier regulator;

2) the connection by which the rectifier regulator feeds the battery
and the fuze box;

3) the ignition switch.

If any of the three bottlenecks makes a bad connection, the owner won't
get good results from his accessory lights and his battery will go dead
and he might even damage the wiring harness connectors.

 

While I'm not familiar with your bike, it's pretty clear.
The OEM alternator circuit was designed/sized for running
with a single (55W.?) headlight.
You just added 110W. of load to the system & rode off.
The alternator was not up to the new load, (probably overheated),
and the battery drained, trying to fill in the extra current.
You might be able to recharge the drained battery, but I am
worried that you may have fried the alternator or the voltage
regulator.
Have them both checked.
MadDog

 

FB,

I agree on all points. It took me a while to realize that the extra
current I was pulling through the stock circuit for heated clothing was
frying the reg/rec connector, but was not blwoing the accessory fuse.

As suggested by the heated clothing vendor, I routed their wiring away
from the stock wiring, drawing current directly from the battery
(through a 10 amp in-line, replaceable fuse and a separate ground wire
to the bike frame). The "new" circuit includes a relay activated by a
running light circuit activated by the ignition on/off switch. I
believe a similar set-up would accommodate the extra lights and perhaps
the fan switch to avoid accidentally leaving these circuits "on".

Manjo

 

Well, hooking the accessory feed directly to the battery does help the
motorcycle's wiring harnesses somewhat by reducing load on the wires
going to the fuse box and the accessory outlet terminal.

But the alternator and the rectifier regulator STILL have to pass the
current to operate the accessories, light the lights and charge the
battery, so the alternator and RR connectors have to be clean and the
connections have to be tight or the connectors will melt.

The only way I can think of to get around this connector problem would
be to install ANOTHER battery that wasn't connected to the motorcycle's
electrical system at all, and run it TOTAL LOSS, recharging it at home
or at work by a battery charger.

There isn't much room on any motorcycle for another lead acid battery,
they are inconveniently shaped and there is no available space.

One poster came up with the idea of wiring a whole bunch of
rechargeable NiCad batteries together in a thin mat that would fit
under the seat of his motoX bike that he wanted to convert to street
use.

A portable NiCad battery pack might not be a bad idea for a commuter
who just rides about an hour to work and an hour home. He could
recharge his battery pack at home and at work.

 

You can, of course, reduce the number of connections in your wiring
harness (and yes, FB has advocated this in the past).

The stock wiring harness on my '94 VFR had a connector for the 3
alternator wires at the alternator. This connector allows the alternator
pigtail to be separate from the vehicle harness. There is another
connector at the RR.

I cut off the connector at the Alternator, soldered the wires together
and and covered the junctions with heat-shrink and weather-seal. This
removes one possible corrosion site from the harness, and it's a
connector that I only ever used to check for corrosion...at that
connector. Going all-out would involve installing heavier-gauge wire
from the alternator to the RR, and then from the RR to the battery. That
eliminates the possibility of melting down the wiring because it's too
small to carry the current without overheating.

This strategy does not allow one to pull more current than the RR or
alternator can supply (without draining the battery), nor does it
prevent overheating the RR, but that's an entirely different subject
(though it too has been covered in this group and in many other places
on the www.

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.

 

It just occurred to me that if you have the automotive style alternator
behind the cylinder block underneath the carburetors that the brushes
might be worn out.

 

Thanks all for the very informative reading! I read all replies and learn
from it all, although as I age I retain less of it. The brushes are indeed
done, cooked to charred little nubs. I suspect they have been on their way
out for some time now, which might explain the premature death of my
previous battery <?> Bought a newsed alternator on eBay and will repair the
old one at my leisure, although my track record with fixing electrical
gizmo's sucks. Still haven't come up with a solution for my inadequate
lighting however.....I liked the suggestion of a Halogen, but since this is
unfortunately a sealed beam headlight, in a size that's not common ....at
least I think it is proprietary to this bike, methinks I'm outta luck there.

thanks again all!
Tom B

 

yoikes! Thanks Mark, I double checked it and you are right, I've never
looked closely at the back of the headlight (joy of a plastic wrapped bike
eh)till now and it is indeed a replaceable bulb. I have some 65/55 "Bright
white's" for my Volvo which I'll try in the bike after I find a heavier
plug. Now I've also learned why the same Volvo burns headlight bulbs at an
alarming rate....last time I changed a bulb my connector was melted and
charred, I thought it was because of the dumbass are I had to wiggle my hand
into to fit the connector, I had just not pressed it on tight enough. When I
bought the brighter/hotter bulbs I was warned about possibly melting the
lens on the lights but since they are glass I ignored that! I'm still lost
on the theory here....if a bulb is 65/55 what difference in current draw or
voltage or whatever other electrical definition can a similar 65/55
"brighter" bulb make? I understand the connections having an impact, (I am
just finishing building a pro street bike out of a KZ750 frame, Z1000
engine and a bunch of ZX parts, and made my own homemade wiring harness
which uses heat tubing wrapped, soldered or soldered and ring terminal
connections).

thanks again!
Tom B

 

A single H4 bulb should be adequate. As for unobtainable parts, ITYF
they're far from that.

 

<VVBG>

Positively avant-garde, in fact.

 

First of all, if your headlight was that dim I'd think your alternator
was going bad to start with. Fix that problem first and see how bright
it is after that, you might not need extra lights at all.

 

..if a bulb is 65/55 what difference in current draw or
voltage or whatever other electrical definition can a similar 65/55
Basic D.C. Electricity - V. (Volts) x A. (Amperes) = W. (Watts)
The Volts can be asumed to be constant at 12 (+/-).
65 Watts. draws 65/12 or 5.42 Amp.s
55 Watts. draws 55/12 or 4.58 Amp.s

B.T.W. - If you really need more light, and don't have a lot of
extr power there are 12 Volt. - 25W. 'narrow spot`sealed beam
units used for tracklighting that might be fitted. If separately
switched
as auxiliaries and used sparingly they might fill your needs.
They would fit the outdoor holders for some tractor lights.

 

yup, just replaced the alternator with a newsed one compliments of eBay and
the light output has improved considerably!

thanks all!
Tom B