How to check alternator output?

Hello!
I have a 76KZ900A4 I am having charging problems so I need to troubleshoot. I checked the voltage at the battery and it pretty much doesn't move as the revs go up. everything is stock. Much thanks!!

got a manual? it would take me 2 hours to type that one out for ya! :laugh:

I got a factory manual

i think charging system is around pge 194 in the factory manual

:dry: My manual only goes to 187

I found it!!
Thanks!!

This should help:

Alternator Testing For the Older 4’s(Z1’s,Kz 900’s, Kz1000’s,Kz1100’s and GPz1100’s).

To check to see if the alternator is working you need to follow these simple steps:

1. Fully charge the battery as this will be the power source during this test.

2. Disconnect the Regulator/Rectifier at the plug that has the six wires in it.

3. Start the engine and let it warm to operating temperature.

4. If you're worried about overheating, position a large fan for cooling the engine.

5. After the engine has reached operating temperature, have a helper assist you, and using a multi-meter, read the output at the three yellow wires (or the alternator output wires)at the disconnected connector.

6. Raise the engine speed to 4000 rpm, and see what the three YELLOW wire combinations(or any alternator output wires) are(1-3, 2-3 & 1-2). The output will be around 50 Volts A.C.(Alternating Current). BE CAREFUL, AS THERE IS A SHOCK HAZARD HERE!!

7. If any of the combinations are low or non-existent, the stator(wire windings) are bad and must be replaced.
Some of the older Z1’s and KZ900’s were phase sensitive, so check the wire colors carefully.

8. Using an OHMETER, Check the three wire combinations again, looking for a reading of 0.36 - 0.54 OHMS. If the readings are above or below, the stator may be bad and need replacement. Also check from any of the three YELLOW wires to ground, this will show if arcing took place.

9. Before ordering a new stator, check the connections from the stator as there are electrical "Bullet" connectors that may be damaged or dirty.
Inspect the wiring for signs of shorting or overheating too. www.z1enterprises.com sells replacement rubber grommets for the alternator output wiring, they get hard and could leak oil after a while.

10. Check the wiring coming out of the grommet as there have been situations where the wires were damaged causing a short(I.E. twisted together with insulation damage).

11. The sprocket cover will have to be removed to access the electrical connectors coming from the alternator, the left foot peg assembly and shifting lever will have to come off also.



I wrote this as general guide for alternator testing, your particular bike may have a higher output than what I've listed.

From the manual....

I'm a little confused MFolks, my 76 A4 has a separate reg/rec the white plug is for the rect. and has 3 yellow wires. The only plug that has all 6 wires has a black, white,green/red,black/yellow,brown,and blue/red. Should I disconnect this and check the VAC at the yellow wires or is this a test for only bikes with a combo reg/rec ?

One thing I should point out though is that I already perfomed a test on the rectifier and fount it to have no resistance that I could measure.

One more thing,should I go ahead and get the reg/rec combo?Is it hard to retrofit?
ThanksB)

P.S. I guess the reason I'm asking how to test my alternator is so I can fix this in one swoop instead of waiting for shipping twice

The earlier Z1's and Kz900's are wired differently than the bikes of the 80's with seperate regulators and rectifiers. Color codes on the wires are again diferent.

If it were me, I'd contact www.z1enterprises.com and order a combo reg/rect. A member here(Old Man Rock) recently had to replace his rectifier as it developed a short in one of the diodes on his bike.

I believe he used a combo unit with no problem.