Voltage Regulator/Rectifier Replacement

[Beau254]

Ok guys. My rectifier went out. Bike was over charging & ruined 2 batteries. They were all swelled up/Pregnant looking. lol. I changed Rectifier out with a new one but I noticed my old one had this Blue wire bridged into the hot lead of the rectifier plug-in. It goes up to the hot post on the battery. Is that necessary? Do I need to bridge it back in to the new Rectifier? Not sure of the purpose of it, but that’s how it came from the previous owner. See pic.

 

[maleko89]

You might want to check charging voltage w/o first. It’s bypassing the main fuse and wouldn’t see a charging inprovement unless the main fuse circuit isn’t up to snuff.

 

[Parminio]

Somebody has a wiring diagram of all of that around here somewhere. I've seen it, I'm sure. Maybe @Fire-medic knows where it is.

 

[Fire-medic]

Note this is for the '85-'89 bikes, it should be similar for 1990+, but for the pick-up coil (5 wires on the first 4 years [grey, green/white; orange; red/white; black], two wires on 1990-2007 bikes) and a couple other places. Note on the diagram above, the pick-up coils are shown on a semi-circular segment to reflect their induction role to the rotor on the end of the crankshaft; the three wires running from the stator to the R/R are hard-wired, there is no polarity issue, so any wire from the stator can connect to the corresponding wires running to the R/R, where the three R/R wires terminate into a three-way plug. You see the red wire from the R/R runs to the 30 amp main fuse. The ground for the early system is the mounting of the R/R to the piece it is bolted to. The later model R/R has a black separate ground wire instead of relying on the bolts fastening the R/R to the bike, providing the ground. It is not uncommon for the three stator wires becoming corroded, and causing overheating at the three-wire plastic disconnect to the R/R. The plastic terminal can brown from the excess heat generated, and will eventually crumble-apart, possibly leading to a short-circuit. For that reason, many people choose to make a 'hard-connection,' they eliminate the 3-wire plastic connector of the early design, and individually-solder the wires, using heat shrink tubing, and perhaps a plastic split-side piece of corrugated plastic wire loom protector over the splice joints.

I'd trace that light blue line to see what it's energizing. Looks like light blue is the neutral indicator circuit. However, if that's just a 'not of this wire loom' circuit and color, you really do need to trace it to see where it leads.

 

[maleko89]

He said the blue wire goes from R/R to (+) battery post. It's not the neutral wire.

 

[Fire-medic]

He said the blue wire goes from R/R to (+) battery post. It's not the neutral wire.

Thanks, I re-read it.

That blue wire is just a jumper to allow more current to get to the battery, maybe the prior owner thought that OEM wire was partially-broken and not delivering sufficient current to the battery. Guess he had some blue-jacketed wire lying-around.

 

[Beau254]

You might want to check charging voltage w/o first. It’s bypassing the main fuse and wouldn’t see a charging inprovement unless the main fuse circuit isn’t up to snuff.

Maybe that’s why it blew the regulator?

 

[Beau254]

View attachment 81124View attachment 81123
Note this is for the '85-'89 bikes, it should be similar for 1990+, but for the pick-up coil (5 wires on the first 4 years [grey, green/white; orange; red/white; black], two wires on 1990-2007 bikes) and a couple other places. Note on the diagram above, the pick-up coils are shown on a semi-circular segment to reflect their induction role to the rotor on the end of the crankshaft; the three wires running from the stator to the R/R are hard-wired, there is no polarity issue, so any wire from the stator can connect to the corresponding wires running to the R/R, where the three R/R wires terminate into a three-way plug. You see the red wire from the R/R runs to the 30 amp main fuse. The ground for the early system is the mounting of the R/R to the piece it is bolted to. The later model R/R has a black separate ground wire instead of relying on the bolts fastening the R/R to the bike, providing the ground. It is not uncommon for the three stator wires becoming corroded, and causing overheating at the three-wire plastic disconnect to the R/R. The plastic terminal can brown from the excess heat generated, and will eventually crumble-apart, possibly leading to a short-circuit. For that reason, many people choose to make a 'hard-connection,' they eliminate the 3-wire plastic connector of the early design, and individually-solder the wires, using heat shrink tubing, and perhaps a plastic split-side piece of corrugated plastic wire loom protector over the splice joints.

I'd trace that light blue line to see what it's energizing. Looks like light blue is the neutral indicator circuit. However, if that's just a 'not of this wire loom' circuit and color, you really do need to trace it to see where it leads.

This is a 92’. I was worried about burnt connectors. But all was good. Didn’t see any burnt wires or plug connections.

 

[maleko89]

Yep, possibly.

 

[Beau254]

You might want to check charging voltage w/o first. It’s bypassing the main fuse and wouldn’t see a charging inprovement unless the main fuse circuit isn’t up to snuff.

That’s what I’m going to do. Fire it up & check charging voltage running.

 

[MaxMidnight]

Ok guys. My rectifier went out. Bike was over charging & ruined 2 batteries. They were all swelled up/Pregnant looking. lol. I changed Rectifier out with a new one but I noticed my old one had this Blue wire bridged into the hot lead of the rectifier plug-in. It goes up to the hot post on the battery. Is that necessary? Do I need to bridge it back in to the new Rectifier? Not sure of the purpose of it, but that’s how it came from the previous owner. See pic.

The 'blue' wire isn't OE and if it is going to the battery it won't be fused. As Mr Medic says, the OE red wire also goes to the battery but via the main fuse (which Yamaha call the sub fuse).

I have read that some will do this and if the r/r has been playing up and may be an attempt at a 'fix' (term used loosely!)

If the r/r is working correctly then the 'blue' wire isn't needed.

 

[Parminio]

If the r/r is working correctly then the 'blue' wire isn't needed.

I wouldn't run it simply down to the fact it bypasses the fuse, so in the event something happens and the fuse blows you're still going to fry the entire assembly because there's now no way to kill the connection.

It literally bypasses the protection the sub fuse supplies.

 

[FancaR]

Some 'my mother and I are great engineers' odd job. Just skip it.

 

[Beau254]

Ok guys. I changed the R/R & have brand new battery. Left the Blue bridge wire disconnected & fired it up & reved it a bit to ~ 3500 rpm. I get 13.25 volts. That’s a little low isn’t it?! Maybe thats why they had it bridged in? Should I try bridging the blue wire in & see if I get better volts? I’m used to ~ 13.8-14.2 V on a car. Not sure if it’s the same for a bike?

 

[maleko89]

Yeah, it's not charging. My battery is 12.8 volts and not running. At 2K and above it's about 14.2 volts.

You can try and see if that makes a difference. Check AC voltage going into each of the three white wire legs but after the stator connection. Rev to 5K and make sure all three legs are close and above 50 VAC. Make sure ground is good/clean and maybe run it directly to battery.

 

[Fire-medic]

Have you done the 'crimp-fix?'

 

[Beau254]

Have you done the 'crimp-fix?'

View attachment 81233View attachment 81234

No , unless that’s the same as my blue wire mentioned bridged into the R/R hot wire direct to hot post on battery?

 

[Beau254]

Yeah, it's not charging. My battery is 12.8 volts and not running. At 2K and above it's about 14.2 volts.

You can try and see if that makes a difference. Check AC voltage going into each of the three white wire legs but after the stator connection. Rev to 5K and make sure all three legs are close and above 50 VAC. Make sure ground is good/clean and maybe run it directly to battery.

I figured as much. But I was getting 17.5 volts when the R/R was zapped running/reving. So I know the stator is charging. If stator is charging why wouldn’t a brand new battery & R/R let it charge??
looks like they had this issue before too if they bridged that wire directly to battery terminal.

 

[maleko89]

I figured as much. But I was getting 17.5 volts when the R/R was zapped running/reving. So I know the stator is charging. If stator is charging why wouldn’t a brand new battery & R/R let it charge??
looks like they had this issue before too if they bridged that wire directly to battery terminal.

That’s true, your stator and connections should be good based on your previous voltsge reading. So try jumping and check your grounding. If that gets your voltage up, Repair main fuse including the crimp mentioned. That crimp is in between battery and splits off to r/r and key switch.

 

[Fire-medic]

That’s true, your stator and connections should be good based on your previous voltsge reading. So try jumping and check your grounding. If that gets your voltage up, Repair main fuse including the crimp mentioned. That crimp is in between battery and splits off to r/r and key switch.

Look at the pics, that's why I included them. Remove the wire loom tape to expose it. A quick solder session and you should pick-up > 1 volt to the harness.