Kawasaki VN750 Forum banner

1 - 20 of 37 Posts

·
Super Member
Joined
·
30 Posts
Discussion Starter #1
So I bought the bike a few weeks ago and I knew that it had an electrical issue. The PO told me that he changed the stator, r/r, battery, fuse box, key ignition and pickup coils, but he couldn't figure out what the problem was. The battery kept dying.
I hooked up my multimeter and noticed that something was draining the battery.
From what I understood the drain was caused by the 3 wires coming from the r/r. the brown and white wires are both connected to the positive battery terminal and the black wire is connected to the negative terminal.( I'm not entirely sure that this is the original R/R since i don't see a black and yellow wire.)
The PO must have wired it that way.
It doesn't seem right according to what the wiring diagram says.
Does anyone have any ideas on how to fix this problem?


 

·
Linkmeister Supreme
Joined
·
7,960 Posts
Well I`m no electrical guru, but it is clear on the wiring diagram that the brown and white wire are not supposed to be spliced together, and neither one should be connected to the positive battery terminal.

Does the engine start and run when it is wired like this?
 

·
Super Member
Joined
·
30 Posts
Discussion Starter #3
Well I`m no electrical guru, but it is clear on the wiring diagram that the brown and white wire are not supposed to be spliced together, and neither one should be connected to the positive battery terminal.

Does the engine start and run when it is wired like this?
the engine runs fine, but the battery dies after a few rides.
Also i don't even have a brown wire in the harness, but i do have one on the r/r. I only have 3 yellow wires , a white, and a black/yellow (5 wires total, but the diagram show 6 wires). so my harness has 5 wires but my r/r has 6.
So even if I rewire it back, i don't know what to do with the brown wire.
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
The three yellow wires carry the charging current from the stator.
You can do a quick check of the charging system by looking to see if the headlight gets noticeably brighter when you rev it up from an idle speed of 1100 rpm, up to about 5K rpm.
The volts should rise from about 12.5 V at idle to 14.5-15 V at 5K rpm.


I believe the brown wire goes to the JB to signal the headlight circuit to come on.
There are some threads from earlier this summer with some colored wiring diagrams that will help you, if you can find them. I`ll take a look and see if I can.
 

·
Premium Member
Joined
·
369 Posts
The brown wire from the R/R will drain the battery when connected like you have it. Connect it to any wire which has voltage only when the ignition is on. Originally it was connected to a brown wire with a white stripe.
 

·
Super Member
Joined
·
30 Posts
Discussion Starter #6
I dont want to wake up the neighbors, so I'll check the charging system tomorrow.
I did however connect the brown wire to the brown/white wire and it seemed to help, but something is still draining it.
i connected my multimeter between the negative battery terminal and the harness like the manual said to do and it reads 66mA with the white wire connected to the battery and 1.7mA with it disconnected.
the manual says that it should be 1.2mA or less.
 

·
Premium Member
Joined
·
369 Posts
i connected my multimeter between the negative battery terminal and the harness like the manual said to do and it reads 66mA with the white wire connected to the battery and 1.7mA with it disconnected.
the manual says that it should be 1.2mA or less.
You mean positive battery terminal and harness? And by white wire you mean the white wire from the R/R (which actually changes to red in your picture)?

In that case you have a low quality (chinese) R/R which discharges the battery in a week.

Does that 1.7mA drop if you remove the main fuse? If yes, does it drop if you disconnect the ignition switch? That 1.7mA is not so bad, it takes months to drain the battery.
 

·
Super Member
Joined
·
30 Posts
Discussion Starter #8
You mean positive battery terminal and harness? And by white wire you mean the white wire from the R/R (which actually changes to red in your picture)?

In that case you have a low quality (chinese) R/R which discharges the battery in a week.

Does that 1.7mA drop if you remove the main fuse? If yes, does it drop if you disconnect the ignition switch? That 1.7mA is not so bad, it takes months to drain the battery.
The main fuse did drop it and so did the acc fuse. Ill check the ignition switch when I get home.
I'd be happy with 1.7mA
Ill swap out the r/r with the one on my parts bike and get back to you guys.
 

·
Member? ... check.
Joined
·
536 Posts
Pappa's closin' in ...
The black wire is battery ground (-)
The white wire is the battery charging wire positive (+)
The brown wire is a control wire. It is used by the R/R to determine when to "shunt" excess voltage to ground. It is a voltage "monitor" wire. It needs to be switched (by the keyswitch) so as not to have the control circuits energized whilst the bike sits waiting for you to ride it.

The headlight relay in the jb is switched and latched in by signal on one of the yellow AC wires from the stator. One of the yellow wires is split to both the R/R and the JB.

hope that helps.
.
 

·
Registered
Joined
·
458 Posts
Z Explains the funtion of the wires to a T. Im surprised no one mentioned just to get rid of that original R/R and replace it with a Mosfet R/R kit. In that case the Brown, WHT/R and the Black wire can be cut and taped up not to be used.
 

·
Member? ... check.
Joined
·
536 Posts
I would suggest first things first Olezhka.
Follow OlHossCanada's recommendation, and do a quick check to see if the charging system is even working while the bike is running. Remember to rev the engine to about 4k, and check voltage at the battery, or maybe even at the R/R's white wire. If it is working, then you may only need to relocate the brown wire connection. If it is not, then you need to evaluate the stator to make sure it is functioning before considering an R/R purchase.
 

·
Super Member
Joined
·
30 Posts
Discussion Starter #12
k so the charging system isn't working too well. it's 12.5 at idle and 13 at 5k.
It's weird but I could have sworn that when I checked it a week ago it was at 14.5 volts at 5k.
the headlight doesn't change
 

·
Member? ... check.
Joined
·
536 Posts

·
Super Member
Joined
·
30 Posts
Discussion Starter #14
I'm not sure I'm doing this right because I've never really used a multimeter until a few days ago. please correct me if I'm doing it wrong

I put it on this setting
and I got 1.1 between all the yellow wires and nothing when grounded
 

·
Member? ... check.
Joined
·
536 Posts
~
That setting and probe connection looks correct for the initial stator tests.
When you check for voltage between the yellow stator wires (bike running), just remember to turn the selector switch to the 200 setting in the ACV section first.
The readings you have so far are good.

repost with your voltage findings.

~~C8>
 

·
Member? ... check.
Joined
·
536 Posts
I guess you know that the 8 ball is giving you pain.
I would double and triple check my readings. Then, If I am sure I have to replace the stator (which the po said he already did), then I would review the thread below.
You should realistically evaluate your skills for this one ...

http://www.vn750.com/forum/showthread.php?t=16839

~~C8>
.
 

·
Super Member
Joined
·
30 Posts
Discussion Starter #18
I guess you know that the 8 ball is giving you pain.
I would double and triple check my readings. Then, If I am sure I have to replace the stator (which the po said he already did), then I would review the thread below.
You should realistically evaluate your skills for this one ...

http://www.vn750.com/forum/showthread.php?t=16839

~~C8>
.
I'm sure that I could have done this myself, but fortunately for me the PO has already done this mod. Replacing it this time should be easy.

I also checked the stator on my parts bike and it seems to be working fine. It passed all of the tests. I bought it cheap because the PO said the stator was dead.

I think I might just fix the parts bike instead
 

·
Member? ... check.
Joined
·
536 Posts
Now that your getting use to using that DVM. I think I would check out the R/R next ...
Here's a link for checking the shunt type R/R. Not knowing what R/R you have, check to see if there is a part number on the unit, and google it.

http://vn750.wetpaint.com/page/Charging+System
 

·
Super Member
Joined
·
30 Posts
Discussion Starter #20
I'm out of town and I should be back on tuesday. I'll check the r/r then and I'll post the results.
 
1 - 20 of 37 Posts
Top