overcharging

[cookie]

took the R90S for an MOT the other day. it passed, but i noticed it was reading high on the voltmeter. 14.25v or so at low revs, rising to nearly 15v @ 5000rpm.

when i got home i swapped the regulator for a known item with no change.

before i go poking about with the meter, can anyone suggest a cause? i rather suspect the diode board myself, but don't have a spare to test.

 

[fritz]

Sorry mate, just re-read your opst, so the below won't apply if you've swapped it I guess. Soz

For a mo' though you meant dealer overcharging !
I rem' this trick is in Haynes manual, in fact I carry a wire just just such ! but this from motobins site - they're lovely helpful folk. Hope this helps.

Voltage Regulators can fail, but are easy to check - just unplug the unit, and connect the blue and black wires of the plug together while the engine is running. If the alternator voltage increases sharply, the voltage regulator was faulty. On the older electromechanical type, the internal contacts are sometimes the culprit, and can be cleaned, but the solid state units must be replaced.

 

[bmwrich58]

Hey Cookie, are you sure the replacement regulator is good?
Try another one,for shit's and grins!!!

I had this problem and inadvertently reinstalled a "bad regulator" I had sitting on the tool bench accidently.
I guess that's why they made trash cans, of course I have a long work bench and nothing gets tossed out.....

The book suggests this regulator to be suspect at first.
Do you have the "Classic Boxer Charging" book by Rick Jones??
This little book is excellant and I believe is the owner of "Motorrad Elektrik". Great pictures, diag charts and it's cheap and small enough to carry in your saddle bag. Currently I can't find an E-Mail for you.

 

[cookie]

trial regulator (solid state type) worked when last fitted on my own bike.

both regulators do something as i bridged it out & volts went even higher.

can't find anything wrong with the charging circuit. maybe it just is a bit high?

not seen the book you refer to.

cannot PM you my email addy as you are not a forum sponsor & i don't want to post it here.

 

[bmwrich58]

cannot PM you my email addy as you are not a forum sponsor & i don't want to post it here.

sorry for the late reply.

my e-mail [email protected]

 

[bmwrich58]

Motorrad Elektrik web site:

www.motoelekt.com

 

[nud1e]

Lights on?

[
can't find anything wrong with the charging circuit. maybe it just is a bit high?

[/B]

Work colleague had similar problem, his mechanic asked if he had checked the regulator output with the lights on.
Lights on and voltage peaking at 14V.

 

[cookie]

Re: Lights on?

Work colleague had similar problem, his mechanic asked if he had checked the regulator output with the lights on.
Lights on and voltage peaking at 14V.

yes, with lights on voltage does indeed drop to 14/14.25ish. nothing at all like my GS (or my mates) which struggle to that sort of output without load.

 

[cookie]

Re: Lights on?

Work colleague had similar problem, his mechanic asked if he had checked the regulator output with the lights on.
Lights on and voltage peaking at 14V.

yes, i have checked that. with lights on voltage does indeed drop to 14/14.25ish. nothing at all like my GS (or my mates) which struggle to that sort of output without load.

 

[Frank Warner]

Err what is it like with the regulator removed?
If no charging takes place without the regulator then it is not the diode bord .. or anything else but the regulator.

Err you certain that the DVM is ok? Just a thought.

 

[cookie]

Err what is it like with the regulator removed?
If no charging takes place without the regulator then it is not the diode bord .. or anything else but the regulator.

Err you certain that the DVM is ok? Just a thought.

if i take the regulator out i get no charge, i think, from memory.

DVM agrees spot on with new voltmeter on dash.

 

[Frank Warner]

Well I'd be very suspicious of the regulator..
If you’re certain that is working .. Then check for shorts in the diodes on the diode board.

 

[cookie]

Well I'd be very suspicious of the regulator..
If you’re certain that is working .. Then check for shorts in the diodes on the diode board.

when i get time, i'll swap it with the regulator out of my own le mans.

 

[cookie]

well,

that's 3 working regulators tried & a brand new diode board with no real change.

 

[cookie]

Cookie

Are you using the BM pod voltmeter - mine have always worked like the old "swingometer" - are you sure the volt meter is not duff

- have you checked the charging rate with somethingelse, (Gunson).


Para

yup, digital voltmeter £10.99 @ machine mart & it does read a bit lower than the (brand new) BM voltmeter.

i'm going back to thinking "that's just how it is" now.

does anyone know if regulators actually have a cut off voltage or do they just dump a percentage of the current after a certain point, 'cos i get two different readings with the same regulator on 3 different bikes?

the R90S is the odd one out.