TOPIC:

Ok... Quick question for the 76 KZ900. The generator sends the current through the rectifer first...then from the rectifer through the regulator....from the regulator the brown wire is sending the current up to the ignition switch...then back down through the white wire past the 20amp fuse into the battery...does this sound correct? I am trying to understand the wiring diagram. I have the new regulator/rectifer combo unit on my bike. There is also a short white lead coming off the combo unit that plugs into a connector going to the battery. Next question is... does the current do a loop through the ignition switch first and back to the battery or is the generating current coming off that small white lead to the battery first? I wish the diagram would have shown which way the current flows.

Kaw900 wrote: ...76 KZ900...trying to understand the wiring diagram....

Don't know if this will help, but basic understanding of the bike's electrical system may aid trouble shooting and understanding of the wiring diagram.

It's important to realize and keep in mind that the ignition system and the charging system are two separate systems.

The charging system's sole purpose in life is to keep the battery charged.
The charging system includes alternator (dynamo), rectifier and regulator.
The alternator generates AC (alternating current) which goes to the rectifier which converts the AC to DC (direct current).
The DC from the rectifier goes to the regulator which maintains correct DC voltage for keeping the battery charged.

All other parts of the bike's electrical system (ignition and chassis such as lights) operate off the battery -- not the charging system -- and don't care how the battery stays charged.

With a good charged battery, and no charging system components whatever, the bike will perform just fine, until the battery runs down.

Here's a simple method to check performance of the charging system:
With all the electrics hooked up, and a good fully charged battery, engine running, with headlight off --- use a voltmeter to measure voltage across the battery terminals. At idle rpm, look for about 13 volts. At 3000~4000 rpm, look for 14~15 volts.

Good Fortune!

Here is a link to OMR's thread and had a great simple schematic for just the charging system.
kzrider.com/forum/4-electrical/382738-voltage-regulator-#382800
AC voltage once converted and regulated will go tho the battery and the load to the main fuse, then from the main fuse to the switch, the brown wire senses load on the system so the regulator knows how much to supply.

The alternator feeds the rectifier and regulator simultaneously. The output of the rectifier should go directly to the battery (sometimes using the connection at the starter solenoid just as a contact point). The ignition switch will not reduce output to the battery, since it is not in that path.

However, if the combo unit is using a brown wire, that is the sense input to the regulator. The ignition switch can drop the voltage on that wire, but that ends up with more output going to the battery. It's only a one-way deal... a bad ignition switch or fuses or wires etc. will result in the combo unit putting out more power (if it's available), but not less.

If there is no sense line, then the regulator uses the rectifier output as the sense line and then the ignition switch has no bearing on the reg/rec output.

The thick white (sometimes red) wire on the combo unit is the output.

I understand. So what else could possibly be the issue of the bike not charging properly? All the charging components check out fine. I'm just not getting the proper voltage back to the battery.

The only time I've encountered this type of problem was on bikes using the Dyna S (or Dyna III) ignition. This uses roughly double the power of the stock ignition, and more if the coils were also replaced with lower resistance ones.

Sometimes it's just enough to weed out the strong alternators from the weak. In your case, it means the rotor. It's possible the magnets are just weak enough that they can't handle the extra load of the Dyna S.

Does your other bike also use a Dyna S? And have you tried swapping rotors?

Patton wrote:

Kaw900 wrote: The charging system's sole purpose in life is to keep the battery charged.

um, well... what if, like me, you don't have a battery? Then what does the charging system do?

If the new unit has the brown sense wire, disconnect from 12v switched source. This should fool it into a max output, 15+ DCV @ Battery. If not then back to checking ACV from Stator before entering R/R.

I know the original points system was replaced by the previous owner with an electronic Dyna System. The coils are Green, pretty sure its a Dyna S. I replaced the stock Stator with a new unit that produces 10-15% more output, when i tested the new stator on alternating current it was producing about 53AC volts which tells me the rotor is strong. How would i be able to test the coils?

Got an AMP meter? You can measure the AMP's pulled by the Ignition system. Running, and all other circuits. With a large enough one, say 30 AMP capable you could measure the total draw/ load, and the the charging system AMP output.

The open-load test checks voltage, but with no amperage. It's not a power test, but just a simple comparison test for stock setups. Since the ignition is using more amperage than stock, I wouldn't rely on the 53 vac number as strong enough to power the extra load. It may be strong enough, but I'm saying I wouldn't use that test as the only say in the matter.

I can't see how the Dyna coils could be the issue because i have an exact same bike with a Dyna S and stock stator with no problems at all. I don't have an AMP meter that reads over 30. Mine only goes up to 10. Would a bad ground somewhere in the wiring harness be causing this issue?