Alternator issue

JustHoward · Oct 10, 2011

If the voltage at the regulator is low with a 100 watt load applied, do I replace the alternator, the regulator, or the rectifier--or is it all one piece? If they're separate pieces, how do I test each one?

Howard

Ignacio · Oct 10, 2011

Define low and how you tested the voltage? Why is it you think you have an issue with the alternator or charging system?

JustHoward · Oct 10, 2011

Ignacio said:
Define low and how you tested the voltage? Why is it you think you have an issue with the alternator or charging system?

I'm reading voltage from my datel. which is wired to the batter.

At regular cruise, it reads 13.9. With my 90 watt jacket, it reads 12.3. With my jacket and 70 watts of HID, it reads 12.0

On the last rally, Iran it this way for about 50 miles, stopped to get gas, and the bike wouldn't start, with the datel going down to 8 volts during the starting attempt. We push started the bike, I left off the HIDs and jacket (brrr), and have had no problems since.

The battery is two months old.

Howard

Ignacio · Oct 10, 2011

The voltages seem low across the board. I think 14.2 or 14.3 with no load is the butter spot having had two FJRs and a Datel hardwired or close to the battery with big gauge wire and a relay.

Has it always shown 13.9 or has that changed? If the former--then is an add-on voltmeter in the process? If so, I'd check with a voltmeter across the batteries to compare.

If the latter, what and when did it change.

160 watts of HID and electric clothing (assuming you've actually measured the wattage and not estimating) seems like a fair amount. You could be in deficit mode.

ToyQuest · Oct 10, 2011

Interesting this just came up.

I added a Datel this weekend in preparation for some Warm-n-Safe gear ordered for the wife. Mine is wired through the Eastern beaver fuseblock on the switched side. Took a long road trip with it on yesterday. Mine '09 reads 13.8 running @ 4k rpms with nothing but a aux V1 detector, Nuvi gps and Starcom digital running. 14.1 was the highest that I saw at well over the 5k rpm needed for max output. That is with low beams running. I thought "that seems low" based on what I've read here.

Going to check it with the Fluke meter tonight to confirm the reading. Bike is an '09 with 17k miles, using the original battery.

ionbeam · Oct 10, 2011

ToyQuest said:
...I added a Date... Mine '09 reads 13.8...14.1 was the highest that I saw...Going to check it with the Fluke meter tonight...

Is that reading battery voltage or switched ignition voltage?

ToyQuest · Oct 10, 2011

That is reading battery voltage. I said switched because it is on the switched side of the eastern beaver fuseblock. The fuseblock is sourced directly from the battery.

I just pulled the battery panel off and confirmed the Datel is correct with the Fluke 179 MM. Here is something I didn't notice yesterday. While the bike was in warm up mode, the voltage was 14.3-14.4 but as soon as it idled back once warm, it idles at 13.5V and no amount of rpms will push it back over 14.1V. Again tested 4k rpm on the road equals 13.8V with only the load documented above.

So the range that I'm working with is 13.5 idle to 13.8 with 4k rpms with minimal additional non-stock load.

huron52 · Oct 10, 2011

ionbeam said:
ToyQuest said:

...I added a Date... Mine '09 reads 13.8...14.1 was the highest that I saw...Going to check it with the Fluke meter tonight...

Click to expand...

Is that reading battery voltage or switched ignition voltage?

What's the difference? Where would you pick up Switched ignition voltage?

Now I have my Datel connected to my switched side of my Eastern Beaver. It is connected just like all my other electrical devices on the switched side of my fuseblock. Power still comes from the battery direct but the trigger relay is fired by the windsheild.

My voltage reads 14.13 or 14.10 there abouts. Running just my Solteks it will drop to about 13.5 to 13.8

I did notice that when I rewired to put in the Easten Beaver fuseblock I got higher readings on my datel than before. Not the start with nothing running (that was the same)but as I put more load on the system there was less of a drop for each device. Could be because I put heavier wire in. Could be because The datel is wired differently..... don't know.

JustHoward · Oct 10, 2011

Is the alternator and the voltage regulator one unit or are they two separate units?

Warchild · Oct 10, 2011

huron52 said:
ionbeam said:

Is that reading battery voltage or switched ignition voltage?

Click to expand...

What's the difference?

You want to read battery voltage to avoid slight voltage drop that typically occurs when reading voltage across switches, relays, or other components.

JustHoward said:
Is the alternator and the voltage regulator one unit or are they two separate units?

Separate.

There are three major components to your electrical system: 1) the alternator (stator), 2) the "R/R" (regulator/rectifier), and 3) your battery. When one has charging woes, it's almost *always* one (or more) of these three components. No absolutely always.... but almost always.

Since the battery is relatively new, let's rule that out for the moment.

While R/R's do go bad, they really don't go bad all that often on FJRs, and if they do, it's usually heat-related on Gen I's; it's rare to have them problematic on Gen IIs.

Which leaves your stator. And/or possibly, wiring-harnesses and their connectors.

Howard... is your stator original? How many miles on it?

If you have a fair number of rally miles on this stator, I would turn my suspicions (and investigations) towards it... so here you go:

Bike Charging System Troubleshooting Flowchart

JustHoward · Oct 10, 2011

Warchild said:
huron52 said:

ionbeam said:

Is that reading battery voltage or switched ignition voltage?

Click to expand...

What's the difference?

Click to expand...

You want to read battery voltage to avoid slight voltage drop that typically occurs when reading voltage across switches, relays, or other components.

JustHoward said:

Is the alternator and the voltage regulator one unit or are they two separate units?

Click to expand...

Separate.

There are three major components to your electrical system: 1) the alternator (stator), 2) the "R/R" (regulator/rectifier), and 3) your battery. When one has charging woes, it's almost *always* one (or more) of these three components. No absolutely always.... but almost always.

Since the battery is relatively new, let's rule that out for the moment.

While R/R's do go bad, they really don't go bad all that often on FJRs, and if they do, it's usually heat-related on Gen I's; it's rare to have them problematic on Gen IIs.

Which leaves your stator. And/or possibly, wiring-harnesses and their connectors.

Howard... is your stator original? How many miles on it?

If you have a fair number of rally miles on this stator, I would turn my suspicions (and investigations) towards it... so here you go:

Bike Charging System Troubleshooting Flowchart

Dale,

I have 75,000 miles on this bike in two and half years with multiple rallies. According to the flowchart, though, everything is OK. At 2500 rpms I get 13.9 volts, and at 4,000 rpms, I get 13.9 volts, all with just the normal load. but when I hook up the HIDs or heated jacket, the voltage drops like a rock.

the mechanics at my dealer can change tires and oil, but I tend to do any 'major' work, because they just don't handle many FJRs.

I have the Yamaha YES warranty, so I'm not shy about getting the alternator or regulator changed if needed, I'm just trying figure out which one I need to change.

3dogs · Oct 11, 2011

This book has a good explaination regarding the charging system and battery plus diagnosing and testing procedures.

Motorcycle Electrical Systems

Fred W · Oct 11, 2011

3dogs said:
This book has a good explaination regarding the charging system and battery plus diagnosing and testing procedures.

Motorcycle Electrical Systems

And if you have any specific questions about the content, 3dogs just happens to be the author.

One and the same.

Warchild · Oct 11, 2011

3dogs said:
This book has a good explaination regarding the charging system and battery plus diagnosing and testing procedures.

Motorcycle Electrical Systems

Indeed. I have a signed copy from the author.

And I'm proud to say..... the book is heavily dog-eared and has many greasy fingerprints throughout the pages. And it stays next to the both Service Manuals out in the garage.

It's an awesome reference..... B)

ionbeam · Oct 11, 2011

If your battery voltage is dropping to 12.0 volts -- HOLY CRAP!!! That's sure not good, your charging system is 110% overloaded and the battery can't supply sufficient make-up current. I can run you through a troubleshooting process if you have a volt meter, access to the voltage regulator and access to the stator connector on the voltage regulator. It almost sounds like you have a wiring problem instead of a charging or battery problem. If you want, I can PM you my phone #.

kaitsdad · Oct 11, 2011

Based upon my personal experience I'd look at the stator output first - Stator Woes

A huge amount of great information from Ionbeam - suggest you read through this all the way.

ToyQuest · Oct 11, 2011

ToyQuest said:
So the range that I'm working with is 13.5 idle to 13.8 with 4k rpms with minimal additional non-stock load.

Should I be concerned with this voltage range given the light load and go digging deeper for a possible developing issue? As far as the bike history, to my knowledge the bike has never had any large additional loads on it. I bought the bike from the original owner with 4k farkle free.miles (so I was told).

JustHoward · Oct 13, 2011

ionbeam said:
If your battery voltage is dropping to 12.0 volts -- HOLY CRAP!!! That's sure not good, your charging system is 110% overloaded and the battery can't supply sufficient make-up current. I can run you through a troubleshooting process if you have a volt meter, access to the voltage regulator and access to the stator connector on the voltage regulator. It almost sounds like you have a wiring problem instead of a charging or battery problem. If you want, I can PM you my phone #.

Alan,

Please PM me with your phone number.

I disconnected the stator connector and tried to measure ohms between the three white wires with a digital voltmeter, and got 00.0 for all three combinations. The service manual says the ohm readings should be 0.13-0.19 ohms. But my voltmeter only measures to tenths, not hundredths.

I've read the previous thread about diagnosing the stator issue. I have one BIG question--is it OK to disconnect the stator connector while the engine is running? Will disconnecting the entire load from the stator cause the thing to blow up and fry itself?

I'm working on my bike at my dealership, but they don't have a lot of experience in this area, so I really would appreciate your help.

Howard

Fred W · Oct 13, 2011

Howard,

I'm sure Alan will be in contact with you soon.

But in the meantime I can tell you that you will not hurt your stator by leaving it disconnected with the engine running. Having it disconnected presents it with a large / high resistance (open) so there will be no current flowing. No current = no damage. You will be starting and running the bike strictly off the battery's charge, which is OK for a short time, while measuring the raw AC voltage from the stator.

My bet is that you will find one of the legs (phases) is low due to some fried stator coil windings.

Good Luck.

PS - Alan is well versed in Alternator failures with lots of personal experience.

Alternator issue

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