Hi all

need some help with honda blackbird electrics,

I have the engine running seems ok,

but the battery light will not go out,

i have checked the battery this is ok 12v, but when engine is running it is only reading around 11 volts on the metre,

i thought that it should be atleast 13+ volts to recharge battery?>?????

question is what could cause this regulator is getting constant 12v power (11.8 to be exact, could it be this???

or the alternator ??? if so whats the best way to check this im not sure,

any help or ideas wecome

thanks every one or if you need further info just reply

thanks again

Its not unknown for alt and reg to go kaput, mate had it happen on his bike only recently

i,m not a bike mechanic but i have a honda vfr, had similar problem which turned out to be the rectifier, common honda failing, gets too hot.
check what power is coming OUT of the alternator ( think its measured in ohms) as the reading from the battery IS low, the battery isn,t telling you anything except what charge its holding, not what its receiving if you follow my drift.
good luck.
andy

Thanks for the replies,

the car has been running for a total of about 10 minutes,

when started the car for first time no problems, then only started a couple of times since the engine has been fitted only on tickover,

i ran the car upto temperature the other day then the battery light started to flicker of then on now it is staying on all the time,

could this more than likely be the regulator then ?????

will have to check if my multi meter has ohms on it to check power from alternator dont think it has??

thanks again and any other ideas welcome

where have you sited the regulator in the engine bay? is it getting hot, yes they get warm with current going thru them but if its too near to another heat source it,ll be breaking down & thus giving a false reading, & if the car isn,t moving then there,s no air flow to help keep things cool.
just a thought, hope it helps.
andy

DON'T TRY MEASURING POWER ON THE OHMS SCALE!

Guaranteed to destroy your test meter.

The average test meter won't handle the Amps either, so stick to the volts range, it's much safer.

Hi i think the ohms range is just for measuring the resistance on the alternator wires to the stator coils without ignition on??

correct me if i am wrong ??

thanks again

Hi Indy Bird,
sorry if my info was misleading,
my vfr battery shows 14.4volts with engine running.
when i had a similar problem to yours the fault i had was traced to a blown rectifier, as said its a common fault with honda,s, tho honda did alter the design of the rectifier in newer models by giving the rectifier cooling fins as in a heatsink idea.
suggest someone with more electrical know how than i,ve got checks it out for you.
andy

Hi

You can check the alternator stator resistance with an ohm meter.

There are 3 yellow wires coming out of the alternator to the rectifier (as it is 3 phase).

The resistance reading between one yellow wire and another will be quite low (about 0.25 Ohms). The stator winding is made from quite stout stuff so normally is not the problem unless the winding insulation has broken down and is shorted to earth. Test this by measuring between the yellow wires and chassis. Should be a high resistance reading.

As previous posts, I also would suspect the rectifer or possibly the connections on big connector that connects the rectifier to the alternator.

When all is well, you should measure about 15v at 5000 revs across the dc output.

Cheers

Mike

when i first read the post i thought rectifier, as others have suggested

It probably is the rectifier, but it would be interesting to chect the output from the alternator before the rectifier, if you can.

Another possibility is that the rotor (which is usually permanent magnet on bikes) may have lost its magnetism

Thanks all for the replies always good to come home from work check locost site and some answers are there,

will check the resistance but not sure if my meter measures that will invesitgate,

failing that maybe change the regulator,

its mounted under the dash to keep away from heat also engine has only been run for about 10 mins total on idle, so no real chance of heat building up i would of thought,

will check all connections again you never know,

if not anyone got a regulator for a carb bird engine or know best place to get them apart from ebay??

thanks again everyone

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Originally posted by INDY BIRD


will check the resistance but not sure if my meter measures that will invesitgate,

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