Big red light

[PW Cymru]

Had the Red charging circuit light come full on this weekend and it's stays on when revved above 3k rpm.

I topped the battery up last week as I'd left it run rather low and havn't run it since the top-up. It's probably a fairly old battery and may have sulphadeted plates.

Would a short between the plates cause the red chargeing light to come on solid.

The static voltage across the terminals is 12.3 v and the battery charger doesn't light the green light like it did before I topped the battery up.

It's an old Oxford charger and I don't have the manual for it.

Hopefully its just a battery or an I into or am I into the mysteries of engine electrickery.

 

[Kenny]

A new rotor is called for my good man

 

[cookie]

A new rotor is called for my good man

if the rotor had gone, the charge light would never come on. it's powered via the rotor windings

i'd check if there's any voltage rise across the battery when you rev the bike (probably won't be).

connections generally. red light stays on if the plug's fallen out of the regulator.

diode board. substitution is probably best. i could post you one if that would help.

 

[Kenny]

Agreed, humble apologies . ( This is what becomes of you when you own a R1100GS !!)

Check she is charging around 14 volts at about 3,000 rpm if so then obviously the alternator ( and rotor ) is working and it is more likely the Regulator has died ( or loose wire as cookie states ). Quick check of the wires to the diode board wouldn't go amiss either.

 

[PW Cymru]

if the rotor had gone, the charge light would never come on. it's powered via the rotor windings

i'd check if there's any voltage rise across the battery when you rev the bike (probably won't be).

connections generally. red light stays on if the plug's fallen out of the regulator.

diode board. substitution is probably best. i could post you one if that would help.

Hi Cookie,

Thanks for that, I can't check it now as I'm off to work for a few days.

Will check the bits when I get home later in the week.

A loan diode board would be a great help.

Many thanks

 

[cookie]

if you want the diode board, PM me your addy as i'm away from next monday for a week.

 

[PW Cymru]

Agreed, humble apologies . ( This is what becomes of you when you own a R1100GS !!)

Check she is charging around 14 volts at about 3,000 rpm if so then obviously the alternator ( and rotor ) is working and it is more likely the Regulator has died ( or loose wire as cookie states ). Quick check of the wires to the diode board wouldn't go amiss either.

Thanks Kenny, I know the bike's volt meter is crap but when I rode it yesterday morning the volt meter didn't get above 12v even when revved it normally reads about 13.5-14v.

I'll take her skirt off on the weekend and fiddle about a bit

Cheers PW

 

[r100gser]

re big red light

hi if you have any other symptoms such as horn or indicators not working, it is worth checking the two relays under the tank, take them out and clean up the contacts and then see if there is any difference, it might just save you time and money..

 

[PW Cymru]

Well checked the regulator and the voltage didn't rise when revved so possibly ok.

Removed diode board and the earths are dirty and corroded, I'll change some terminals, board mounts and run an extra earth directly back to the battery to back-up the 2 std earths.

Is there a procedure to test the diode board?

 

[Bryn]

if the rotor had gone, the charge light would never come on. it's powered via the rotor windings

My light flickered, and it was the rotor that was knackered..... put it down to a break in the windings, which connected when the rotor heated up and expanded

Anyway, new rotor, and then it was fine

 

[PW Cymru]

We have life

Thanks to Cookie fitted a new diode board, 4 new diode mounts, replaced the 2 earth leads and run a new additional earth from the diode board back directly to the battery with a spur to the loom earth on the coil bracket.

The old diode board although not confirmed as completly dead was corroded with high resistance across the earth points, burnt out earth lead and generally shitty and corroded every where.

Generator light now goes out at about 1200 rpm instead of the 2000 rpm.

Now for the test run.