Shindengen Mosfet FH080 replaced stock R/R

[bezsv650]

My stock R/R was wreaking havoc on my batteries and my Ignition control unit. I replaced with a genuine Mosfet R/R in accordance with the guidance on this site. Diode test on new R/R is good, I checked the stator resistance and voltage values are good. The voltage across the battery is 12.4 Volts Idle BUT doesn't increase with revs. Please help me.

[Seeker]

The first thing I'd be interested in is the output from the stator. Disconnect it from the reg/rec. There are 3 wires coming out of the stator (often yellow), call them 1,2 and 3 - measure the AC voltage at idle and at, say 5k rpm - measure 1-2, 2-3 and 3-1. At 5k rpm I'd expect to see > 60Vac - this is an estimate but it should be a high value and similar on all 3 measurements.

[bezsv650]

The first thing I'd be interested in is the output from the stator. Disconnect it from the reg/rec. There are 3 wires coming out of the stator (often yellow), call them 1,2 and 3 - measure the AC voltage at idle and at, say 5k rpm - measure 1-2, 2-3 and 3-1. At 5k rpm I'd expect to see > 60Vac - this is an estimate but it should be a high value and similar on all 3 measurements.


Yes, for all connections I'm getting around 30v idle and 60v at 5K rpm consistent numbers for each combination. Resistance = 0.4 Ohms across each connection also.

[admin]

This might help.

https://www.aberdeenbikers.co.uk/motorcycle-charging-system-diagnosis-checks/

Sent from my SM-T510 using Tapatalk

[GeorgeRYoung]

The resistance from the (disconnected) stator to ground should be infinite, or thereabouts.

[bezsv650]

The resistance from the (disconnected) stator to ground should be infinite, or thereabouts.
I'm getting OL for resistance from stator terminals to ground. Getting 0.1 ohms for -ve regulator connector to ground.

[bezsv650]

The resistance from the (disconnected) stator to ground should be infinite, or thereabouts.
Thanks, that's a very useful guide. I think everything is checking out. your article suggests I need to check the grounding from R/R . Not sure how best to test that I'm getting a resistance reading of 0.1 ohms from -ve terminal of R/R to -ve terminal of battery

[Seeker]

another thing to check is the condition of the wiring between the stator and the reg/rec, paying particular attention to plugs/sockets. Look for corrosion and signs of burning. Some people bypass the bike's loom and connect the stator directly to the reg/rec using 12 or 14 gauge wire, then connect the reg/rec directly to the battery via a suitable 30A fuse.

[glang]

so does it look like no charge is getting to the battery? What happens to its voltage reading while running when you put more load on it such as main beam?

[admin]

Thanks, that's a very useful guide. I think everything is checking out. your article suggests I need to check the grounding from R/R . Not sure how best to test that I'm getting a resistance reading of 0.1 ohms from -ve terminal of R/R to -ve terminal of batteryThe bolts holding the reg to the frame should ground it so do a resistance test from those bolt to somewhere else on the frame (engine bolt?).

Sent from my SM-T510 using Tapatalk

[bezsv650]

another thing to check is the condition of the wiring between the stator and the reg/rec, paying particular attention to plugs/sockets. Look for corrosion and signs of burning. Some people bypass the bike's loom and connect the stator directly to the reg/rec using 12 or 14 gauge wire, then connect the reg/rec directly to the battery via a suitable 30A fuse.
Thanks. Nothing I can notice, the cables appear fine.

[bezsv650]

The bolts holding the reg to the frame should ground it so do a resistance test from those bolt to somewhere else on the frame (engine bolt?).

Sent from my SM-T510 using Tapatalk
just tested the R/R bolts. they seem to have good connectivity to several ground points including the engine - thanks.

[Seeker]

from what you've described, you have the correct voltage going into the reg/rec but the incorrect voltage coming out. Occam's Razor suggests your reg/rec is faulty.
Was it new or used?

[bezsv650]

from what you've described, you have the correct voltage going into the reg/rec but the incorrect voltage coming out. Occam's Razor suggests your reg/rec is faulty.
Was it new or used?
new, I guess it must be the R/R - thanks again for your help

[glang]

we still havent checked if theres actually an output from the RR by changing the load have we?

[bezsv650]

we still havent checked if theres actually an output from the RR by changing the load have we?
glang, please explain how I can check for that

[admin]

glang, please explain how I can check for thatDisconnect the reg/rec from the loom (but not the stator) and check the output voltage, is it still low? If it's much higher it should mean there is something on the bikes electrical system dragging down the voltage.



Sent from my SM-T510 using Tapatalk

[glang]

Im not sure the RR can control its output voltage correctly without being connected to the battery - I know on cars they say never disconnect the battery with the engine running...
So I was suggesting measuring the battery volts with engine running while changing the system load. If the RR is working the voltage wont change and if not the voltage of the battery will drop as only it is supplying the demand.
The extra load could be from headlight main beam but better would be heated grips or some other 12v load connected across the battery.

[admin]

Im not sure the RR can control its output voltage correctly without being connected to the battery - I know on cars they say never disconnect the battery with the engine running...
So I was suggesting measuring the battery volts with engine running while changing the system load. If the RR is working the voltage wont change and if not the voltage of the battery will drop as only it is supplying the demand.
The extra load could be from headlight main beam but better would be heated grips or some other 12v load connected across the battery.This is true. I only did this for a few seconds. Another way is to temporarily connect directly to the battery, or even a spare one of you have one available.

Sent from my SM-T510 using Tapatalk

[bezsv650]

thanks guys, will try on the weekend

[yorkie_chris]

This is true. I only did this for a few seconds. Another way is to temporarily connect directly to the battery, or even a spare one of you have one available.

Sent from my SM-T510 using Tapatalk

You can fry some regulators scarily quickly running them without the load of a battery to stabilise the voltage.

Not saying this is surely the case with a modern MOSFET one, but don't risk it.


To me, it sounds like the regrec is dead on arrival. But check the output voltage direct at the regrec just in case, there is a big live connection in the loom that can rot out, and also the main fuse holders and connection are pretty weak, they have been known to get hot and burn out... but I suspect this would manifest in other gremlins.

[bezsv650]

Im not sure the RR can control its output voltage correctly without being connected to the battery - I know on cars they say never disconnect the battery with the engine running...
So I was suggesting measuring the battery volts with engine running while changing the system load. If the RR is working the voltage wont change and if not the voltage of the battery will drop as only it is supplying the demand.
The extra load could be from headlight main beam but better would be heated grips or some other 12v load connected across the battery.
voltage does drop slightly when I use the head lamps / break lights

[Seeker]

But check the output voltage direct at the regrec just in case

Did you try this as yorkie_chris suggested? It will be difficult to get the probes into the back of the connector (the connector must not be disconnected for the test). If you measure a higher voltage at the reg/rec it implies there's a problem within the bike's loom. If you measure the same voltage as measured at the battery it implies the reg/rec is faulty.

If this proves impracticable, you could see if a regular spade connector would fit the reg/rec socket and make a couple of temporary 12 gauge lead connections between reg/rec and battery (ideally with a 30A fuse in the positive lead - but for quick test it would be ok without - but don't cross the polarities - you'll get smoke).

A better way would be to get the correct plug but then you need a crimp tool unless you know a friendly auto electrician (I'm sure most would crimp a new lead for you for a beer or two). In case you do, they sell the plugs here: https://www.corsa-technic.com/category.php?category_id=101
and here: http://easternbeaver.com/Main/main.html

[bezsv650]

Did you try this as yorkie_chris suggested? It will be difficult to get the probes into the back of the connector (the connector must not be disconnected for the test). If you measure a higher voltage at the reg/rec it implies there's a problem within the bike's loom. If you measure the same voltage as measured at the battery it implies the reg/rec is faulty.

If this proves impracticable, you could see if a regular spade connector would fit the reg/rec socket and make a couple of temporary 12 gauge lead connections between reg/rec and battery (ideally with a 30A fuse in the positive lead - but for quick test it would be ok without - but don't cross the polarities - you'll get smoke).

A better way would be to get the correct plug but then you need a crimp tool unless you know a friendly auto electrician (I'm sure most would crimp a new lead for you for a beer or two). In case you do, they sell the plugs here: https://www.corsa-technic.com/category.php?category_id=101
and here: http://easternbeaver.com/Main/main.html
Am I to check this voltage while the bike is running ? Do I scrape off the wire coating - how do it do it? Please confirm.
see image http://bezalely.net/wire.jpg

[bezsv650]

You can fry some regulators scarily quickly running them without the load of a battery to stabilise the voltage.

Not saying this is surely the case with a modern MOSFET one, but don't risk it.


To me, it sounds like the regrec is dead on arrival. But check the output voltage direct at the regrec just in case, there is a big live connection in the loom that can rot out, and also the main fuse holders and connection are pretty weak, they have been known to get hot and burn out... but I suspect this would manifest in other gremlins.
can't see any rotting so I suspect you are correct with the regrec DOA. Please see my response to seeker.

[glang]

It certainly does look that way especially as the volt drop with load means its the battery thats supplying it and not the RR. However the final check before you condemn it is as suggested above, check its output volts with the engine running. Can you not get thin pieces of stiff wire into its +ve and -ve connectors to carefully measure without disconnecting it?

[Seeker]

Am I to check this voltage while the bike is running ? Do I scrape off the wire coating - how do it do it? Please confirm.
see image http://bezalely.net/wire.jpg

Yes, the bike has to be running because we want to see the output of the reg/rec measured at the reg/rec and yes, your diagram shows where you would be measuring. There will be power on the red lead even with ignition off.

There isn't a good (easy) way to do this which is why I suggested making up a replacement lead using regular spade connectors, bypassing the bike's loom altogether for a test.

You could scrape off the insulation but the risk of damaging the wires would be high. You could pierce each wire with a pin and measure the voltage between the pins. I'd stagger the pins so they're not level with each other to reduce the chance of shorting them, but you will need to ensure nothing touches any metal parts of the bike.

[redtrummy]

When testing sealed wires I attach the meter leads to sharp knife blades and then press the blade through the insulation onto the wire. Never caused a problem.

[bezsv650]

thanks for all of your help guys, when I replaced some of the wiring the output voltage went up and solved the proble.

[admin]

That's good news.

Sent from my SM-T510 using Tapatalk