KZ900 Volt Regulator question...

I am looking at a '75 KZ900 that fried the coils and
ignition, found out that the previous owner had put
a new volt reg. on this bike and had the wiring all
screwed up. White plug was unplugged and the green
female part of the volt reg. plug was removed and the
wires were each pushed into a hole where the white
plug needed to be. I plugged the white plug where it
needed to be, but the green plug, volt reg. side is
missing, there are 5 wires coming out of the volt reg. Green receptical is missing from wire ends.
Can anyone tell me where these wires go?
green plug as below, on the bike
0 0
x 0 x= no wire
0 0

rectifier wires as below,
0-yellow
0-red
0-yellow
0-black
0-yellow

Post edited by: 762shooter, at: 2006/09/20 16:40

Post edited by: 762shooter, at: 2006/09/22 00:55

There is a wiring diagram for a 76 900 in the filebase. I just took a look at it, and the stock rectifier had 5 wires.

3 wires are connected to the alternator, (3 different colors on this diagram) which probably hook to the 3 yellows you have. On my 650 the alternator wires are all yellow, and I think it's common for Kaws to use yellow at the alternator.

1 wire went to the battery for power, the last wire went ground. I will GUESS the red is the power and the black is the ground.

Check the diagram and make sure you are correct, please don't take my word for it. I'm just taking a good guess after all....but I did rewire a 750 reg/rectifier into my bike when I switched over ignition systems. The wires were diff colors but after looking at enough wiring diagrams I figured it out.

Good luck and have fun!

I have edited the original post to reflect what I
really meant. OKC_Kent, sorry that it looks like I'm
talking one part and your answering another.
BTW,I think I now have the problem solved, the wires
are staying cool instead of melting and when I put
my volt meter on the battery it shows the following,
give or take a tenth or two.

12.4v at rest and idle,
13.2v to 13.5 reving up and,
14.3 when the volt reg kicks in.

Thanks OKC for showing me the wiring diagram.

Back to square one, main fuse,(which is the only
fuse), blows almost as soon as the bike starts.
Have checked this thing inside out for shorts in
the wiring and have found nothing. I have changed
out the rectifier so I am leaning towards a new
regulator. Is there a way to check the regulator
while it is off the bike. The shops I have talked
to want 2-300 bucks for a regulator and like 150
for a used, and then you don't know what you are
getting. I am starting to think about the sledge
hammer repair method, as this is getting real
aggrivating, if anyone has any ideas to toss out,
I'm all ears.

Maybe one of these from Z1E? If in doubt, give them a call.

www.z1enterprises.com/detail.aspx?ID=445

www.z1enterprises.com/detail.aspx?ID=261

The voltage regulator's job is to regulate the voltage (duh!) to your battery. Your's is clipping the voltage at 14.3, and that's perfect. Don't know what else may be going on with your wiring/charging system, but it looks right from the regulator to the battery.
Good luck.

762shooter wrote:

I have edited the original post to reflect what I
really meant. OKC_Kent, sorry that it looks like I'm
talking one part and your answering another.
BTW,I think I now have the problem solved, the wires
are staying cool instead of melting and when I put
my volt meter on the battery it shows the following,
give or take a tenth or two.

12.4v at rest and idle,
13.2v to 13.5 reving up and,
14.3 when the volt reg kicks in.

Thanks OKC for showing me the wiring diagram.

How long did you let the battery charge before checking your voltage?
If the old memory bank serves me, a battery can read even less than what you measured and still over charge, if the charge current is too high but the battery has not yet had time to reach full capacity.
Do you observe any water loss in your battery or does it get hot?
This may be totally the wrong approach and there is nothing wrong with your regulator. The fused circuit may just be over-loaded. Has someone gone in and added another circuit, with significant power consumption?

This bike had a "then fresh" about a year old now,
battery. It was fully charged and showed like 12.4
to 12.6 volts, if I remember right. There has not
been anything added to the bike except a Dana
ignition. The original owner had a new regulator
put on this bike and that guy had the wiring all
messed up, so I think that it might need another
regulator. Sorry, I will back up a little farther
on this, the BOZO speed shop guy who worked on this
for the original owner, did the following wiring
trick, he unpluged the rectifier and cut the ground
wire off of it, he then didn't put the green plug
on the new regulator, but instead pushed the bare
wire ends into the female plug on the bike. Not
only were they not secured with the plug and loose
fitting, but HERE IT COMES, they were pluged into
the slot where the rectifier was supposed to be.

What is throwing me off is the irregularity of the
problem, it might blow 5-6 fuses as soon as it
starts or it may start and be ridden 10-20 miles
before blowing the fuse. My thinking would be that
if the regulator was the bad link then it would
blow fuses each and every time because the regulator
didn't switch off the charge. Could the regulator
be intermitently bad like that?

Sorry to run on so long but this thing has already
cost my dad a Dana ignition and a coil, so I don't want to keep guessing with his money.

762shooter wrote:

.... I don't want to keep guessing with his money.

Do you own a good Digital Multi Meter? If so, we can do a few checks and narrow down which branch circuit the bulk of your current is going into.
If interested, PM me and let's see what we can do. I might suggest you try this first and see if it is right for you. ELECTRICAL fault_finding in the filebase, not model specific section.
It has not helped me out a whole lot, but you will probably have more luck there, than did I.

It sounds like a short somewhere, not necessarily a reg prob.

A common cause is wiring under the tank, if the coils have been replaced. Make sure the contacts on the coils are not shorting against the frame.

loudhvx wrote:

It sounds like a short somewhere, not necessarily a reg prob.

A common cause is wiring under the tank, if the coils have been replaced. Make sure the contacts on the coils are not shorting against the frame.

Is it even close to normal for there to be only one fused circuit? Even with nothing actually in bad need of a electrical repair, one fuse don't seem like enough. :dry:

Most of the KZs have three fuses. The 20A that comes off the regulator/rectifer lead that is teed and goes to the fuse and also the battery. The other two fuses are fed by switch VDC coming back from the ignition switch.