1977 KZ750 Twin Charging Issues

That circuit no worky

Let me rephrase that.

I don't believe the regulator circuit will work as you have it drawn.
But just to cover my butt, I'm going out to the shop to find my manual and have a look at the wiring diagram.

Ok, I'm correct, the regulator has a 12 volt feed from the ignition switch, a brown wire, it connects to the regulator and to the alternator coil.

Did you leave that wire out of the drawing? Or is it missing from your bike?

Nice drawing

Apparently it's missing! I just checked the wiring diagram I have on my computer and it should have a wire going to the ign switch (tee's with the brown wire on my diagram.... interesting. I need to check that out, would that cause it to not charge the battery but still show voltage at the points shown? I guess I need to fix that to find out for sure... Thank you steell for your continued support of my KZ problems :silly:
:laugh: I figured the drawing may help I been through the wiring looking for all day. And broke my speedo cable on a test run this morning But got a new one already.....Big thanks to Clem's Kawasaki in Logansport...nice guys...

--Chad

Clem's Kawasaki, aka OSR, aka Old School Racing,
and I think his son is still a member here, and is
definitely a member of another board I frequent.

Sure hope we have this figured out, it's definitely
possible that we have discovered the problem

Hooked the regulator to the brown wire from the ign. switch (well actually t-tapped it in) and still no charging at the battery level. Still at "point a" to "point b" I get great voltage, better now than before, but I still get a 2volt drop across the negative cable and a 1.3~1.4 volt drop across the positive cable, and They're brand new . I'm thoroughly stumped on it now. Thought we had it when I completely overlooked a wire. Probably got something else I dunno about going on too. (I am temporarily using crimp connectors on this whole mess until I get it work right, then I plan to go back and shorten wires and solder/shrink tube it all.) I've been fighting this same problem since I got the bike 2 years ago... Guess it's just part of the fun of trying to appease the KZ Gods.

--Chad

As steell pointed out, you also need 12v to the field coil. Did you connect 12 v to the field coil's brown wire also, and verify you have 12v there? If the battery voltage is low, the green wire should show close to zero volts. This means the field coil is getting full voltage to produce a field.

You can bypass the regulator for testing purposes to check the alternator. Wire 12v to the brown wire on the field coil and ground the green wire on the field coil. That should force full output at the stator wires, but don't rev the engine while doing this without closely monitoring the voltage on the battery. If it goes above 15v, stop revving. If the battery voltage goes up (when it didn't with the regulator) then the problem is the regulator or its conections.

However, you say you have full charging voltage from point A to point B. Do you mean 14+ volts? That means the alternator and regulator are working fine, so you don't really have to mess with them. If you run jumpers from point B to battery's negative terminal and point A to battery's positive terminal, you still get good voltage at A and B and low voltage at the battery?

Hooray!! The Calvary has arrived!!!

Thanks for posting Lou, this one has me stumped,
I simply can't understand how this could be happening.
How in the world can he get a 2 volt drop on a battery cable????????

It has to be a bad cable or a bad connection, but cables have been replaced
and connections cleaned, and the 2 volt drop is still there.

Sure wish I had the bike here so I could take a good look at it.

Load that thing up and bring it over here (or charge the battery and ride it), I'm about 35 miles from Marion. No charge, I just want to beat that problem into submission!!!!

Hmmm, Monticello, new windshield and soft luggage, 60-65 mpg, wonder what the weather forecast is for this weekend?


.

The weather is suppose to be nice all weekend I'm off on Saturday... Hmmm...lol I'd love to bring it down to have you help but I just recently sold my truck and I don't think it will fit in my Accord or my Wife's Vibe . To Lou I've tried running jumpers and tried replacing the cables I'm moved the ground point to different spots in the frame. my wiring is a little "Cluster F'd" at the this point, with lots of crimp ons and such in the area at this point, but that is only for testing and I will clean it all up with solder and heat shrink as I figure out what the heck is going on. I wish I had the faith in the bike to make the trip, but I dunno on the battery part, I mean I've put a good 120 + miles on it one day but when I got home the battery was only at like 9 volts :blink: . I will try to by pass the regulator to see if that helps, but I am getting 14.5~14.7 V at "point a to point b" at around 3~4k. At idle at those points its still at 13 or above. Thanks for everyone's help and Steell your welcome any time here for your great help so far. (and if you really wanna look at it shoot me a pm and we'll talk and see what we can figure out what we wanna do) Thanks Everyone....

--Chad

Disconnect the battery and measure the resistance from the battery end of the negative cable to a good ground (like the motor). Also measure the resistance from the battery end of the positive cable to the solenoid positive post.

How old is the battery?

Battery was bought in May (or around there) it tests good on the battery tester at my work (shows 173 CCA) There is no resistance by my meter on the cables. The voltage drop only shows when the bike is running.

Gotta Head back to work now though... Further testing will have to wait til around 8 or so

-Chad

It's sounding more and more like a floating ground.

Disconnect the wire between the regulator and the field coil, then measure the resistance between the wire going to the field coil and battery ground.

Then, before reconnecting that wire, turn on the key and measure the voltage between the regulator side of that wire and battery ground.

Don't forget to switch modes on your meter

Assuming you mean the green wire...between the regulator and the field coil... Resistance (on the 200 setting) reads 55.8 ohms, and Voltage with the key on is 12.09 (which is what the battery is at (need to charge it)... What's it tell you ? I have another field coil if mine is bad... I replaced it when I replaced the old stator and I believe my old field coil was ok. What's this floating ground? I feel anxious that we're getting close... :laugh:

--Chad

I hope you have a manual to look up the resistance spec for the field coil, because that part of my manual got dissolved by battery acid.

Did you try the test that Lou suggested? Disconnect the field coil from the regulator and apply 12 volts directly to the field coil. Do not rev the motor while doing this. Measure the voltage between positive and negative terminals on the battery, if it hits 15 volts immediately shut the bike off or unhook the field coil.