Lights dim when revs drop to idle

Originally Posted by forklift

i thought that may be how to do it, just got to work out which mode to select on the meter as it is not clear to me.

PS: don't suppose you live near Sudbury Suffolk UK

No i don't. Put the meter onto volts setting (200v) AC i think or 20v. You'll know if you switch the voltage settings you'll pick up something. Just stick with AC if i'm correct.

[yorkie_chris]

Originally Posted by forklift

The battery reads 13.10 volts with the engine at 5000 rpm with lights on and full beam on as per the Hanes manual. I will try the alternator test but where do the positve and negative meter probes go, in the alternator end connector where the 3 yellow wires are? So do i put them in and check all 3 wires in turn with the + and - on each wire until all 3 have been done. I really hope it is not the alternator cos i do not have a puuler to get the the part. I bumped up the revs to 1300 rpm at idle and the dash lights flicker when i put an indicator on.

You don't need a puller

Originally Posted by thefallenangel

No i don't. Put the meter onto volts setting (200v) AC i think or 20v. You'll know if you switch the voltage settings you'll pick up something. Just stick with AC if i'm correct.

Yes 200VAC scale to check the alternator output.

if there's a problems 99 times out of 100 it's the reg/rec. They're as shizzle as the metal is on an SV. Mine's less than 2 years old and the chain adjuster was seized solid yesterday.

I now realise i used DC voltage measurements and not AC. The machine did not have instructions until i downloaded some today. i'll re-check the 'regulated voltage output' again tommorrow and i'll bet it is within the correct parameters. I now am beginning to think that maybe the battery terminals were not tight and ther V twin engine loosened them off so when i came to start it the connection was so poor it was struggling. If this is the case i feel a right fool, for posting the thread and wsting everyones' time, BUT i will have learnt something...

I replaced my reg this weekend and tested to be sure...

Old 5000rpm lights off 13.4 volts.
Old 5000rpm lights on 12.5 volts and dropping.

New 5000rpm lights off 13.1 volts.
New 5000rpm lights on 13.4 volts.
New 5000rpm lights and heated grips 13.7 volts.

I think the values are right but its from memory, I do know that when I had the lights on with the bike on the old rec it was making the battery flat.

Hey Grinch here's an update.
got home and did the following checks:

Current leakage 0.0mA so below the excess as per the manual so okay
No load unregulated voltage output 83 volts for each yellow wire from the alternator end. Manual says min 70 volts so ok.
Went to double check regulated voltage output and got readings going down very fast ONLY to realise i had not reconnected the alternator connection. So now a dead battery placed on Optimate and back to normal, well 13 volts, manual says 13.0 - 13.2.
Could i have damaged the alternator by forgetting to re-connect or am i just running the bike from the battery until it dies?

Did you do a stator cooil test to confirm the alternator was ok and how much did you pay for the reg/rec.

I have seen them for £80 on line?

regards


Forklift

[yorkie_chris]

If alternator is putting out 80V it is fine. You won't damage it with running it not connected.

Recharge and check regulated output

Reg-rec about £40 usually.

thanks Yorkie

I think I paid about 20 quid for the last one from here, but it was second hand. Its probably lasted about 10K before it died too. The last one came with a job lot of stuff, so it was just lucky. I never checked the stator, as I have had them fail too and its rather different symptoms. It was easy to see what was at fault when I swapped it as I didn't get the voltage drop I had seen before. Things are much easier to check when you have them to swap, and I have 2 SV's, so it helps a lot.

managed to do all the relevant checks including ohms and have sourced a new reg/rec from LM Spares for £62 including VAT and P&P. Will double check the regulated output when fitted and hopefuly this will be it.