Battery voltage drop after fans turns ON

[himanshu23]

Hey all

This is my 2nd post regarding long unresolved issue I am facing in my 2011 Gen II hayabusa.

In my last post, regulator & rectifier unit is found to faulty as stator coupler is melted. Hence it was replaced along with new battery (YTZ14S).


last week I had noticed :

1. When engine is cranked battery is struggling to provide current. Ignition turned off and cranked again. Engine started. But I had a doubt.
2. While riding I had noticed that when Cooling Fans turns ON, horn pitch is reduced/down. Fans turns OFF everything OK. This repeated 5-7 times.
3. When I reached home I had immediately checked charging voltage which was around 13.2V when fans were OFF & High beam ON at IDLE condition.
4. When Fans turns ON voltage dropped to 12.5~12.9V but doesn't rise to 13.2V at Idle condition, engine need to be revved to reach 13.5V.
5. Lastly I wanted to check generator assy. as per manual resistance across terminal should be 0.2~0.7 ohm. but in my vehicle it is around 0.8~0.9 ohm.
6. On removal of stator 4 coils are more reddish than other.

please help me out I am fade up with time situation.

 

[Kiwi Rider]

@himanshu23 ....
Questions:
Did you fit OEM parts or aftermarket Chinese parts when you last replaced stator and reg/rect?
Did you replace the melted connector plug with good quality parts?
Did you check the magnets on the rotor for damage? ( ie cracking or insecurity?)
After installing new parts, did you check the AC voltage at all 3 phase wires of the stator (yellow wires) for around 20vAC at idle and around 70-80vAC each at 6000rpm?
Did you check continuity from the stator connector plug thru to the Voltage reg/rect connector plug?
Also, that yellow volt meter is a cheap one, ($3.70USD) and when getting down to 1 ohm or less, may very well be inaccurate so I suggest using a quality meter for accuracy.

 

[himanshu23]

@himanshu23 ....
Questions:
Did you fit OEM parts or aftermarket Chinese parts when you last replaced stator and reg/rect?
Did you replace the melted connector plug with good quality parts?
Did you check the magnets on the rotor for damage? ( ie cracking or insecurity?)
After installing new parts, did you check the AC voltage at all 3 phase wires of the stator (yellow wires) for around 20vAC at idle and around 70-80vAC each at 6000rpm?
Did you check continuity from the stator connector plug thru to the Voltage reg/rect connector plug?
Also, that yellow volt meter is a cheap one, ($3.70USD) and when getting down to 1 ohm or less, may very well be inaccurate so I suggest using a quality meter for accuracy.

Answer :
Stator is not replaced only connector (male/female) replaced with new one. Reg/rect is new OEM (suzuki)
Melted connector replaced
No damages on rotor assy.
55~65V at 5K rpm
Continuity not checked from stator connector plug to reg/rect.

will verify again with another multimeter.

 

[Kiwi Rider]

Answer :
Stator is not replaced only connector (male/female) replaced with new one. Reg/rect is new OEM (suzuki)
Melted connector replaced
No damages on rotor assy.
55~65V at 5K rpm
Continuity not checked from stator connector plug to reg/rect.

will verify again with another multimeter.

Is the stator output around 20v AC at idle?
Is the voltage reg/rect OEM or aftermarket?
I had an aftermarket reg/rect on my Busa and the voltage output was low, about the same as yours. I had slow starter motor cranking when engine at normal temp, and if I left the bike standing/parked for 2 weeks the battery went flat so I was always having to charge the battery (battery was near new).
I fitted a genuine Suzuki part (reg/rect) and it cured all my electrical charging system issues, it now charges at 13.8v at idle, and 14.6v while riding at 3800rpm (100kmh). I can leave it parked up for a month and it still starts instantly with good cranking speed from the starter motor.
Also, your bike's cooling fan is working a lot more than many of the members' bikes here, I'm assuming you're in India with high temps daily.... and the fan will run constantly, which is very demanding on the battery/charging system.
I'm in New Zealand and it's a temperate climate, even when sitting in traffic the fan only comes on if it's a warm day, like around 25degC.
In your country you will experience over 40degC regularly, correct?

 

[himanshu23]

Is the stator output around 20v AC at idle?
Is the voltage reg/rect OEM or aftermarket?
I had an aftermarket reg/rect on my Busa and the voltage output was low, about the same as yours. I had slow starter motor cranking when engine at normal temp, and if I left the bike standing/parked for 2 weeks the battery went flat so I was always having to charge the battery (battery was near new).
I fitted a genuine Suzuki part (reg/rect) and it cured all my electrical charging system issues, it now charges at 13.8v at idle, and 14.6v while riding at 3800rpm (100kmh). I can leave it parked up for a month and it still starts instantly with good cranking speed from the starter motor.
Also, your bike's cooling fan is working a lot more than many of the members' bikes here, I'm assuming you're in India with high temps daily.... and the fan will run constantly, which is very demanding on the battery/charging system.
I'm in New Zealand and it's a temperate climate, even when sitting in traffic the fan only comes on if it's a warm day, like around 25degC.
In your country you will experience over 40degC regularly, correct?

Yes I had changed reg/rect with OEM in Aug month this year along with new battery.

Yes in India temp. Is around 35~40 degree

Just need to know whether stator is ok or not

 

[Dopey]

Yes I had changed reg/rect with OEM in Aug month this year along with new battery.

Yes in India temp. Is around 35~40 degree

Just need to know whether stator is ok or not

So following the tests your doing is the only way to know for sure. Be sure to test each wire and make sure none of the have a short to ground as well. You definitely have an issue with at least one of the components and with the plug having melted it most likely put some extra wear on everything. Even with that being a cheaper meter like kiwi pointed out the stator is already testing at the end of its limits and over so with all your issues I'd be replacing the stator and rectifier if it was in my shop but I understand those are some expensive parts. Definitely go with an oem stator, the only rectifier I suggest my customers use aside from oem are the ones from "Ricks stator". I'm sure that's not what you were hoping to hear but that's your best bet to not end up stranded.

 

[himanshu23]

Hey all,



A update regarding the concern :



Exact issue : when engine is running cold charging voltage is maintained at 14.2V at idle, when engine reaches 100*C, both fans turn ON, it is clearly visible that headlight got dim and severe load on bike electrical system. Charging voltage drops to 12.5V. On disconnecting any of the fan coupler charging voltage is 13.5V.

I had checked Fan operation with hand both of them were operating freely. Dismantled motor no deris/dirt, carbon leads are also fine. Checked load operations : 3.86A through out running. Only during initial start it shoot upto 8A then maintained at 3.86A.

Checked fan relay : NO sulphation/oxidation, pristine condition of contacts. Relay checked for functioning working absolutely fine.

Checked : Wire short from generator coupler to rectifier coupler, no short to ground. Individual wire has continuity.



Please help me out what is the exact issue. I am frustrated all winter season is going on with rides.

 

[himanshu23]

Hello everyone

I am requesting everyone my help me out for this issue, what could be the possible cause and rectification !