Faulty reg/rec or alternator or both?

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magg
Senior Member
Posts: 1916
Joined: Mon Sep 20, 2010 11:55 pm
Bike owned: VFR400
Location: Blue Mountain NSW Australia
Re: Faulty reg/rec or alternator or both?

Post by magg »

It would be useful to have a stator resistance measurement of 0.1 ohms resolution but the stator output voltage is typical of a functional unit. Your battery voltage with the engine running is too low, should be over 14 volts but less tahn 15 volts with headlight on lowbeam, I suspect a dud rect/reg.
Baz
Settled in member
Posts: 104
Joined: Wed Sep 05, 2012 8:47 pm
Bike owned: VFR NC30 (91)
Location: South Yorkshire
Re: Faulty reg/rec or alternator or both?

Post by Baz »

Hi guys. Sorry for being away for a while after all your help but out of my 4 kids, 3 of them have spent time at hospital over the last couple of weeks and the bike was the least of my problems. All are ok now and we are almost back to normal. So back to the bike. I filled the tank and gave it a good run to eliminate bad fuel (happened to me once with a car, it ran crap until I refilled it then was fine again??) and after a week in the garage on the trickle charger was fine on Friday and got me to work ok this morning but struggled to start on the way home. I have just ordered a new reg/rec so will fit it when it gets here in a couple of days and let you know how it goes.
Cheers guys, Baz.
Baz
Settled in member
Posts: 104
Joined: Wed Sep 05, 2012 8:47 pm
Bike owned: VFR NC30 (91)
Location: South Yorkshire
Re: Faulty reg/rec or alternator or both?

Post by Baz »

Strangest thing.....
Put new reg/rec on and now battery voltages are 13v at 2000 revs and 12.8v at 5000 revs. Any ideas why it would drop with revs on? I bought a brand new reg/rec specifically for the NC30 cos I didn't want to mess about with wiring changes and it is apparently an upgraded version. It is exactly the same dimensions as the old one but has fins on rather than being smooth. It also has the part number SH603-12 on it and the old one had SH609-12 on it. Is this the correct reg/rec?
magg
Senior Member
Posts: 1916
Joined: Mon Sep 20, 2010 11:55 pm
Bike owned: VFR400
Location: Blue Mountain NSW Australia
Re: Faulty reg/rec or alternator or both?

Post by magg »

Because the rect/reg output is not directly connected to the battery. IMHO you might find this post useful:

viewtopic.php?f=24&t=37039&hilit=wiring+upgrade#p267124
Baz
Settled in member
Posts: 104
Joined: Wed Sep 05, 2012 8:47 pm
Bike owned: VFR NC30 (91)
Location: South Yorkshire
Re: Faulty reg/rec or alternator or both?

Post by Baz »

how do I view the post? it wont let me click on it and it doesnt find anything if I search for it?
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JZH
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Re: Faulty reg/rec or alternator or both?

Post by JZH »

Have you tested the battery, yet?

Ordinarily, a brand new reg/rec should not result in the bike not charging. Your charging voltage is still too low, so maybe the old reg/rec wasn't knackered after all, but at least you can now rule out the reg/rec. ;)

So, that leaves the stator, the wiring and the battery as possible culprits. Start looking for burnt connectors and wires, methinks...

Ciao,
JZH

London, UK/So.Cal., USA
www.vsource.org
magg
Senior Member
Posts: 1916
Joined: Mon Sep 20, 2010 11:55 pm
Bike owned: VFR400
Location: Blue Mountain NSW Australia
Re: Faulty reg/rec or alternator or both?

Post by magg »

Sorry my stuff up, try this link:

http://400greybike.com/forum/viewtopic.php?f=24&t=37039

A quick check that the output of the rect/reg is ok is to measure the voltage directly at the rect/reg +ve and -ve output terminals. If you are getting 14 volts then all is ok and only the wiring between the rect/reg and battery needs re-arranging as per the info in the link.

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