Regulator/Rectifier Wiring - Need Advice

[Geek_Law]

Okay, I need some advice.

My charging system was kaput. Took the bike into the dealer and for $100.00 they told me the regulator/rectifier was bad, and further that the stator was putting out low voltage. So I installed a new stator.

Sean sent me a brand new regulator/rectifier. This is where I'm having trouble. First off, the old one does not even get hot. The new one does. The old one if I measure DC voltage at the black and red leads, swings wildly, and the higher the RPM, the more it pumps out. The new one pumps out around 5v when at idle and smooths to around 4v when revved to 2k rpm and higher. I'm not certain I'm doing the measurement quite right, but there is a shocking difference between the two units.

Now here is the problem. In the pics below, there are three white wires that all plug directly into the three white wires from the stator. No problem.

There is a black wire that plugs into a black wire to the neg battery terminal. No problem.

There is a red wire coming from the regulator/rectifier that has no home. This is where I measure some output voltage, around 4-5 on the new one and all over the place on the old one. But where does this wire go?

I realize I sound like a moron now, so here is how I got into the mess. I had a little white OEM regulator/rectifier. When I took that out, it had a red wire coming out of it, that was snipped and taped over. It didn't go anywhere. Unless the dealer snipped it during their diagnostics, the bike had been running in that state for the nearly two years I have had it. I stupidly threw that unit away, and installed a used regulator/rectifier that I had from the seller. That is the one that measures voltage all over the place and does not get hot. It had the red wire, but no home.

Now I have Sean's unit which seams to be working, but there is no home for the red wire. With just the white and the black hooked up, I do not see an increase in voltage on the battery when the bike runs. It just sits right between 12 and 13 volts whether on or off. With the lights and everything "on" but not running, there is a small parasitic drop down to almost exactly 12v.

So, does the wire need to be hooked up? There is no lead for it coming from the battery or the bike. Can I just hook it up to the positive batter terminal? Or am I going to screw something up?

Here are some pics of the wires. Any help is much appreciated. If somebody could trace where their red lead from the regulator/rectifier goes ... that would be awesome.

 

[shicks16]

I wired my red wire to a 30 amp fuse and hooked it directly to the positive battery terminal. I also cut the end of the black wire, soldered a black extension on it and wired it directly to the case ground where the negative battery ground goes which is by the right foot peg. Dis it ever function properly? Without the red wire connected I would think the battery wouldn't keep charged as the charging system positive wasn't hooked up

 

[Geek_Law]

I wired my red wire to a 30 amp fuse and hooked it directly to the positive battery terminal. I also cut the end of the black wire, soldered a black extension on it and wired it directly to the case ground where the negative battery ground goes which is by the right foot peg. Dis it ever function properly? Without the red wire connected I would think the battery wouldn't keep charged as the charging system positive wasn't hooked up

Thanks Shicks. You have given me the confidence to simply hook it up to the RED terminal. I'll put an in-line fuse to the wire for good measure.

Now then ... was it ever hooked up. Pffft. I don't have a clue. I never looked. A few weeks ago I started having these problems, took it into the dealer, they said the reg/rec was bad and the stator was putting out low voltage.

I took the bike home, and that was the first time I looked. I took off the LH panel and the LH rear peg assy to get to the OEM reg/rec and that's when I see that the red wire is not hooked up.

WTF?

Did the dealer cut it? I don't know. But I do know that I've put about 3.5K miles on the bike. It seems if it was never hooked up, I would have discovered that long, long ago.

Who knows. I'm gonna wire it in and see what happens.

I'll post an update after I get it wired in. Gonna try right now.

 

[Geek_Law]

UPDATE and STATUS:

Based in Shick's input, I hooked up the red lead from the regulator/rectifier to the battery. I stole the black plastic end from the old regulator, and hooked it up to an in-line fuse wire that I hooked to the battery. So now I have a fancy receiver for the red lead from the regulator/rectifier.

Then I plugged it in, started the bike ... and ... drum roll ... nothing exploded. Not even the 25A fuse in the new lead.

So then I measured voltages again.

Everything off = ~12.5v
On but not running = ~12.3v or so.
On and running at idel = ~13.0v.
On and revved at 2K to 3K rpm = ~13.7v to 13.9v.

So now there is an increase in voltage when the bike runs. This does not solve the mystery of how the bike was running before. I have no idea what happened to the red lead.

But the charging system appears to be operating now.

The last test will be to drive the bike to work and back and see if I have a dead battery. The last time I tried that, the bike started coughing and choking and died just as I was turning onto my street ... and I coasted to my driveway.

Hopefully I have a fully functioning bike again.

Thanks again Shick16.

Here is a pic of my new lead:

 

[Geek_Law]

POST TEST RIDE UPDATE:

Well, I am 90% certain that my problems are now fixed. I just took the bike on a several mile romp. When I got home I turned it off, and then a few seconds later, tried to start it. It turned over strong and started right up.

Before if I did the same thing, it would either turn over weakly and pathetically, or simply not turn over at all, maybe click a little bit. This is despite having a brand new battery as of maybe 6 weeks ago.

So I think it's sussed out. The real test will be a much longer drive, but I think things are looking up.

-GL

 

[SpecOps13]

I think you've gotten solid advise here. You should be GTG now...

As for an explanation, some 89-90's are possessed....... I have one
named SkullDuggery.... Lots of weird shit happened in the restoration
process and it's still unexplained as to how it was fixed.

 

[Rhoy Carter]

On mine the red wire from the RR pluggs in to the red wire that goes to the main fuse

 

[shicks16]

Yeah I believe the red wire connects to the main line to the battery with a crimp. From what I have read this is actually a bit of a failure point and where the "crimp fix" is done. I just wired in my own fuse with a #12 wire (a little over kill but I wanted to get rid of all doubt that it was the wire) straight to the battery which by passes the crimp all together, cut off the end of the red cable (which apparently you don't have anyways), put a heat shrink over the end, taped it up, and put another wire from the black wire on the regulator to the battery ground on the right side by the foot peg. I am now getting 14.5 volts at start up. One more piece of advice is to solder the connections if you haven't already done so and to use heat shrink over the connections. I used the heat shrink with the glue inside to make a nice air and water tight seal

 

[Geek_Law]

SpecOps suggests that 89-90 maxes are sometimes possessed. I think that's the best explanation so far.

I'm gonna go insane if I try and figure out what happened to that magic wire. I think I'll just thank my lucky stars that I'm up and running.

 

[rollin thunder]

UPDATE and STATUS:

Based in Shick's input, I hooked up the red lead from the regulator/rectifier to the battery. I stole the black plastic end from the old regulator, and hooked it up to an in-line fuse wire that I hooked to the battery. So now I have a fancy receiver for the red lead from the regulator/rectifier.

Then I plugged it in, started the bike ... and ... drum roll ... nothing exploded. Not even the 25A fuse in the new lead.

So then I measured voltages again.

Everything off = ~12.5v
On but not running = ~12.3v or so.
On and running at idel = ~13.0v.
On and revved at 2K to 3K rpm = ~13.7v to 13.9v.

So now there is an increase in voltage when the bike runs. This does not solve the mystery of how the bike was running before. I have no idea what happened to the red lead.

But the charging system appears to be operating now.

The last test will be to drive the bike to work and back and see if I have a dead battery. The last time I tried that, the bike started coughing and choking and died just as I was turning onto my street ... and I coasted to my driveway.

Hopefully I have a fully functioning bike again.

Thanks again Shick16.

Here is a pic of my new lead:

I was wondering what the red wire with the black thing connected to it above your set up is?.

 

[wildweasel_pt]

Its an inline fuse holder... Looks like the main 30A fuse coming from the RR...

 

[Geek_Law]

The red is coming *in* from the stator coils or the RR (don't remember) ... into that little plastic harness ... then to the opposing plastic harness where the yellow tape is ... then into the "black thing" which is actually an inline 25A fuse, and then smack into the positive battery terminal.

Stated differently, the red wire and black thing is just a positive lead and fuse.

That is the wire that was magically missing from my bike. I've been back to riding the beast with no issues ... but it is a complete mystery where the original wire went.

 

[rollin thunder]

I have that too and my fuse is like 7amps.

 

[rollin thunder]

What gage wire do you use for the negative wire that goes to the left side cover to ground it.most motors turn over harder when cold then hot .I had a Yamaha rt 360 single cylinder that when it was cold it could break your leg kick starting it but ,once it was warmed up it was much easier to start.

 

[Geek_Law]

I don't recall what gauge wire. It seems like it was around 12, but it may have been 14.

 

[rollin thunder]

I don't recall what gauge wire. It seems like it was around 12, but it may have been 14.

I went to the Auto parts store today and picked up 8 feet of 10 gauge wire ,some eyelet connectors and a 30 amp fuse like the one you have.I hope this works ,I spent over 20.00.

 

[Geek_Law]

I went to the Auto parts store today and picked up 8 feet of 10 gauge wire ,some eyelet connectors and a 30 amp fuse like the one you have.I hope this works ,I spent over 20.00.

$20.00 sounds like a pretty good dealer.

I had mine diagnosed at the dealer for $100.00 and then was shocked when they asked for around a $1,000.00 to fix her up!

I about flipped out.

I got some goodies from Sean and from some other random internet dude, tore into the bike, and all said I think I put around $300.00 and some time into her.

Hopefully you can get your issue sorted quickly and inexpensively.

 

[rollin thunder]

$20.00 sounds like a pretty good dealer.

I had mine diagnosed at the dealer for $100.00 and then was shocked when they asked for around a $1,000.00 to fix her up!

I about flipped out.

I got some goodies from Sean and from some other random internet dude, tore into the bike, and all said I think I put around $300.00 and some time into her.

Hopefully you can get your issue sorted quickly and inexpensively.

Wow!!!,you spent some cash.

 

[Geek_Law]

Wow!!!,you spent some cash.

Well, that was for a new stator, a new regulator/rectifier, new seals, and some wiring. Plus that diagnosis.