How to check R/R voltage on a Gen II?

SkooterG · May 26, 2016

Long story. I'll try to keep it brief.

I seem to have some low charging voltage at the battery terminals on my 104k mile 09 FJR. I want to check the voltage at the output of the regulator/rectifier. I am in the middle of a move and my 09 service manual is packed in some box and I have no idea where it is. So.......

- Where is the R/R on a Gen II FJR? How do I get access to it?

- How (where) do I check it's output voltage?

Mucho thanks........

JamesK · May 26, 2016

SkooterG

The R/R on the GenII is located near the rear shock, you don't need to remove any parts to get to it.

You'll find that your problem is most likely the one many of us GenII owners have faced before, it's due to the cheap-ass underrated wiring Yami used for this circuit.

The solution is to bypass the OEM wiring going from the R/R to the Battery with a min. 12AGW wiring, for both +ve & -ve leads. You can choose to use either a regular fuse or a circuit breaker (they are both about the same size).

Dcarver did a lot of research on this a few years back and has documented it very well on the forum, I just don't have a chance right now to search for it.

You can of course scrounge up the needed parts from eBay, etc. or Jack makes a complete plug & play kit for this with the circuit breaker included.

Super harness with 30 amp circuit breaker

https://roadstercycle.com/index.htm

SkooterG · May 26, 2016

JamesK said:
SkooterGThe R/R on the GenII is located near the rear shock, you don't need to remove any parts to get to it.

You'll find that your problem is most likely the one many of us GenII owners have faced before, it's due to the cheap-ass underrated wiring Yami used for this circuit.

The solution is to bypass the OEM wiring going from the R/R to the Battery with a min. 12AGW wiring, for both +ve & -ve leads. You can choose to use either a regular fuse or a circuit breaker (they are both about the same size).

Dcarver did a lot of research on this a few years back and has documented it very well on the forum, I just don't have a chance right now to search for it.

You can of course scrounge up the needed parts from eBay, etc. or Jack makes a complete plug & play kit for this with the circuit breaker included.

Super harness with 30 amp circuit breaker

https://roadstercycle.com/index.htm

Thanks!

So I have found the R/R. Looking from the left side of the bike, which connector is the output? Left or right? (Damn I wish I had my SM!) I assume I unplug the output connector and check voltage on the R/R where I unplugged it? From my forum search, I should have 15.4V.

Yes, I have a trusted technical source within Yamaha who was almost willing to bet me it was degraded wiring from the R/R to the battery. (The same thing happened to his '06 FJR) I am getting 13.1-13.4v at the battery terminals.

Since I am going through a move it's difficult to work on my own shit right now, and will be for some time. The 09 was a few days within the 5 year Y.E.S so I took it to a dealer. I told them what was going on and what I suspected. After having it two weeks they returned it to me and told me everything checked out ok - 14.0+ volts everywhere. WTF?!?!?!?! Before I left I had the service manager check the battery terminal charging voltage and his POS voltmeter was bouncing around but reading around 13.4v. He just stared blankly at me. **** them, I brought it home and verified I am still at a charging voltage of 13.1-13.4v at the battery terminals. I want to verify my R/R output voltage is correct so I can take it back to them and tell them to fix this POS Gen II FJR correctly this time and do it for goddamned free under the extended warranty!!! Grrrrr.......

Perhaps I'll just fix it myself with that nifty kit you provided info for. Thanks! But this weekend the g/f, I, and her 21 year old son move into an 1100 sf apartment with no freaking garage until we find a house to buy. My life sucks. I keep telling myself that in 3-6 months all will be good.

I vaguely remember Carver's thread and the wealth of research and information it supplied but as of yet haven't found it.

RossKean · May 26, 2016

SkooterG said:
I vaguely remember Carver's thread and the wealth of research and information it supplied but as of yet haven't found it.

https://www.fjrforum.com/forum//index.php/topic/146331-krzy8-gen2-charging-circuit/?hl=roadstercycle

PhilJet09 · May 26, 2016

My '09 has degraded to about the same voltage at the battery as yours. I have the direct wire kit, but have been too lazy to install it. I'm sure it'll fix it. I've been watching the voltage decline slowly the last few years.

I'm not sure I'd remove the plug to test the output voltage at the regulator, backstabbing the connector seems a safer option. I seem to think some regulators don't like to not have any load. I could be completely full of gówno. Hopefully Alan will be along to correct me.

audiowize · May 26, 2016

PhilJet09 said:
I'm not sure I'd remove the plug to test the output voltage at the regulator, backstabbing the connector seems a safer option. I seem to think some regulators don't like to not have any load. I could be completely full of gówno. Hopefully Alan will be along to correct me.

This is a good idea, with the bike running, you really want to know the difference between the voltage at the battery and the voltage available at the R/R.

JamesK · May 27, 2016

PhilJet09 said:
My '09 has degraded to about the same voltage at the battery as yours. I have the direct wire kit, but have been too lazy to install it. I'm sure it'll fix it. I've been watching the voltage decline slowly the last few years.
I'm not sure I'd remove the plug to test the output voltage at the regulator, backstabbing the connector seems a safer option. I seem to think some regulators don't like to not have any load. I could be completely full of gówno. Hopefully Alan will be along to correct me.

The R/R uses sealed type Furukawa QLW250 connectors, sticking meter probes into the back of them will most likely damage the seals, resulting in leaks and corrosion in the future, especially given the location of the GenII R/R. The MOSFET R/R is intelligent enough to not blow up when not loaded, i.e. disconnected battery side connector. I (and I am sure Dcarver) have had that plug off many times during the original diagnosis and testing of this problem.

JamesK · May 27, 2016

SkooterG said:
JamesK said:

SkooterGThe R/R on the GenII is located near the rear shock, you don't need to remove any parts to get to it.

You'll find that your problem is most likely the one many of us GenII owners have faced before, it's due to the cheap-ass underrated wiring Yami used for this circuit.

The solution is to bypass the OEM wiring going from the R/R to the Battery with a min. 12AGW wiring, for both +ve & -ve leads. You can choose to use either a regular fuse or a circuit breaker (they are both about the same size).

Dcarver did a lot of research on this a few years back and has documented it very well on the forum, I just don't have a chance right now to search for it.

You can of course scrounge up the needed parts from eBay, etc. or Jack makes a complete plug & play kit for this with the circuit breaker included.

Super harness with 30 amp circuit breaker

https://roadstercycle.com/index.htm

Click to expand...

Thanks!

So I have found the R/R. Looking from the left side of the bike, which connector is the output? Left or right? (Damn I wish I had my SM!) I assume I unplug the output connector and check voltage on the R/R where I unplugged it? From my forum search, I should have 15.4V.

Yes, I have a trusted technical source within Yamaha who was almost willing to bet me it was degraded wiring from the R/R to the battery. (The same thing happened to his '06 FJR) I am getting 13.1-13.4v at the battery terminals.

Since I am going through a move it's difficult to work on my own shit right now, and will be for some time. The 09 was a few days within the 5 year Y.E.S so I took it to a dealer. I told them what was going on and what I suspected. After having it two weeks they returned it to me and told me everything checked out ok - 14.0+ volts everywhere. WTF?!?!?!?! Before I left I had the service manager check the battery terminal charging voltage and his POS voltmeter was bouncing around but reading around 13.4v. He just stared blankly at me. **** them, I brought it home and verified I am still at a charging voltage of 13.1-13.4v at the battery terminals. I want to verify my R/R output voltage is correct so I can take it back to them and tell them to fix this POS Gen II FJR correctly this time and do it for goddamned free under the extended warranty!!! Grrrrr.......

Perhaps I'll just fix it myself with that nifty kit you provided info for. Thanks! But this weekend the g/f, I, and her 21 year old son move into an 1100 sf apartment with no freaking garage until we find a house to buy. My life sucks. I keep telling myself that in 3-6 months all will be good.

I vaguely remember Carver's thread and the wealth of research and information it supplied but as of yet haven't found it.

@ScooterG, just buy the R/R kit I linked to from Jack and install it, it's really easy (pretty much plug & play) so you will not need much in the way of tools. I opted for the 50A circuit breaker (and 10AWG wires) rather than the 30A one he's got listed, you just need to ask him for the 50A version... Honestly I think 12AWG wires with the 30A breaker will be totally sufficient.

If you do this mod It will be a one-time permanent fix!

I've had this setup running for over 100k miles now, and am always getting around 14.2V on the Datel with the normal load, well plus a bunch of little farkles that are always on. Even with the 2x30W LED Aux lights and the Baja HID lights on I still get around 13.9-14V at the Datel at around 2500+ RPM.

gapiob · May 27, 2016

I'm not sure I understand everything. If the goal is just to check if the R / R works, just put a multimeter to the battery terminals, then start the engine. We see imediatly the rise of tension, and if you accelerated, the tension rises.
The GEN II actually had to strap problem between the regulator and the battery, but a HS battery gives the same symptoms, and it is much faster to test.

Donal · May 27, 2016

gapiob said:
I'm not sure I understand everything. If the goal is just to check if the R / R works, just put a multimeter to the battery terminals, then start the engine. We see imediatly the rise of tension, and if you accelerated, the tension rises.

The GEN II actually had to strap problem between the regulator and the battery, but a HS battery gives the same symptoms, and it is much faster to test.

All that is true BUT....... if the wiring between the regulator (R/R) and the battery has deteriorated and is showing higher resistance you will not know that by measuring the voltage at the battery.

You can either simultaneously measure the voyage at the R/R and battery and noting the difference.

or

You can measure the voltage DROP on the positive (and then the negative) line by connecting a DMM between R/R positive and battery positive (and repeating that with the negative line).

Fred W · May 27, 2016

Measuring the output of the R/R unloaded (disconnected from the output load) will not tell you anything.

Heck if you were able to measure the voltage at the battery unloaded it would be full voltage too, since with no current through the suspect wiring there would be no voltage drop.

The input to the R/R is the connector with the three gray wires (3 phase AC from stator), the output is the 2 wire connector with black and red wires (positive and negative DC). Back probe the output connect with two thin probes (needle) that will not damage the silicone seals.

eflyguy · May 27, 2016

Another way to test with sealed connectors is to insert a couple of single strands of stranded wire (i.e. very fine) into one end of the connector in such a way that it is accessible when the connector is put back together with its mate. I've done this many times. OBVIOUSLY make sure the wires can't short against each other or anything else.

dcarver · May 27, 2016

JamesK said:
PhilJet09 said:

My '09 has degraded to about the same voltage at the battery as yours. I have the direct wire kit, but have been too lazy to install it. I'm sure it'll fix it. I've been watching the voltage decline slowly the last few years.
I'm not sure I'd remove the plug to test the output voltage at the regulator, backstabbing the connector seems a safer option. I seem to think some regulators don't like to not have any load. I could be completely full of gówno. Hopefully Alan will be along to correct me.

Click to expand...

The R/R uses sealed type Furukawa QLW250 connectors, sticking meter probes into the back of them will most likely damage the seals, resulting in leaks and corrosion in the future, especially given the location of the GenII R/R. The MOSFET R/R is intelligent enough to not blow up when not loaded, i.e. disconnected battery side connector. I (and I am sure Dcarver) have had that plug off many times during the original diagnosis and testing of this problem.

True. No damage done.

Skooter, my recommendation is don't let the dealer touch your 09. Buy the kit,run the wires, be done with electrical charging issues forever.(**) it might take you all of 2 hours get done, working slowly and having a brew or two along the way.

**Unless, of course, you cook the stator but that's an entirely different situation.

lnewlf · May 27, 2016

OK-I'm gonna ask this and duck......where do the red and black wire eyes attach...battery? and is it necessary to replace the grey 3 wire connector RR input?

ionbeam · May 27, 2016

The Red/Black DC wires from the R/R go to the starter relay where they attach to a heavy threaded studs. The two studs are the points where the smaller gauge R/R wires connect to the heavy gauge battery wires.

There is no need to do anything with the three gray AC wires that connect to the stator unless the DC voltage at the R/R is low while the Red/Black output wires are connected to the R/R. If the basically nominal load on the electrical system causes the DC output of the R/R to be low then it's time to troubleshoot the stator and R/R.

Panman · May 27, 2016

Battery Yes. Forget the Grey. Unplug the stock harness, wrap it up good and poke it some place out of the way.

Cold my 07 would maybe hit 14 volts when cold and degrade fairly quickly. I could only run my heated coat or grips on low now I can have both on medium let it run and let the radiator fans kick in at idle and all stays working.

mcatrophy · May 27, 2016

I'm having trouble keeping out of this, so, as it's Friday, I won't.

The original wiring put in by Yamaha is adequate for the task. If it was inadequate, no FJR could maintain its battery charge.

Assuming the stator and the RR are OK, what deteriorates are the connectors. A tiny bit of corrosion can cause a lot of voltage drop when you are dealing with several tens of amps.

Replacing the loom will clean the connectors on the RR. So will unplugging the original, cleaning the connections, putting on a little anti-corrosion stuff, and replacing.

It is also possible the crimping of the wires in the pins corrodes. Squeezing with pliers will provide a temporary improvement. Soldering the wire to the pin would provide a more permanent cure (there are those who say soldering is unsuitable for automotive use, if that's a worry to you, replace the connector pins and re-crimp, though you may find the wire too short. Personally, I'm quite happy to solder).

There, I feel better now.

lnewlf · May 27, 2016

allrighty then- my trusty Datel shows bat v gradually dropping from 14 to 13.9 to 13.8 which may indicate a developing problem...simple things first- I'll try mcatrophy's suggestion first...then meebee the above mentioned replacement super harness. As per ionbeam the R/B wire eyes should attach to the starter relay posts in place of the oem RR wires.

ionbeam · May 27, 2016

lnewlf said:
allrighty then- my trusty Datel shows bat v gradually dropping from 14 to 13.9 to 13.8...

That may not be entirely true. Under different operating conditions there was often a significant discrepancy between what my Datel read for voltage and what my DMM showed when they both were directly across my battery terminals. I have put an O'scope on my Gen I and found a lot of 'noise' on the +12 volt line. Different meters deal with the noise in different ways resulting in different readings, this is one time where an old school needle type meter may actually provide a more accurate reading.(1) I would very much like to have a chance to put an O'scope on a few electrical systems to see what is truly going on.

(1) Since it's Friday I'll spare y'all a long, dry, boring explanation of why

How to check R/R voltage on a Gen II?

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