Dead Battery

[CHRISZZR600]

Hi all, it's my first time here, so be gentle ..lol. I went down to the garage tonight to go for a ride on my 83 xl600r. I put in the key,and the neutral light came on, she started first kick, so off i went with the headlight on as usual. After about 10 miles i prepared to take a left turn, i flicked the switch...nothing..no flashing at all. I did a hand signal and took the turn and pulled up. I noticed that the neutral light was now very very dimly on. Headlight was still on and fine....no indicators, no neutral lamp,no tail lamp,and no horn...i decided to turn round and go home. When i got back i checked the battery voltage..2.4 volts.!! So i disconnected it, and it started to recover,eventually to 5.6 volts. MY question is..do you think it's the reg/rectifier? or the alternator?...I'm not brilliant with electrics, but i do have a meter and some test leads/lamps. Whats the best way to test this?..Battery,(recharged) back on and run the bike and check the volts across the battery? All help gratefully recieved, and sorry to ramble..Chris.

[Pigford]

So, obviously no charge getting to battery! (assuming you've checked battery terminal conections are tight).
Next check all connections from altermator thru to battery & any others you can see!
For a start, with bike running, check power into & out of reg/rec unit. This will see if it is the reg/rec or the alternator playing up.

[CHRISZZR600]

Thanks Pigford,i'm charging the battery tonight,and it seems to be ok. I'll take a look tomorrow eve when i get home....i'll let you know the results. Thanks again mate..Chris.

[ade]

i had a very similar problem recently...
to cut a long story short,water got into the indicator flasher can and shorted it out and blew the fuse..
changed the fuse and normal service was resumed....

[CHRISZZR600]

Thanks ade...i'll check that tomorrow too. Fuses all look fine,no corrosion and all intact,but i'll check the ind.can. Cheers,Chris.

[ade]

i noticed the reg/rec was very warm..no where for the current to go.
i sealed the flasher can up with 2 part epoxy.since then i have been in rain and through fords and no probs.
i changed the fuse from glass to blade fuse c/w holder

[CHRISZZR600]

Thanks again ade.....i'll get a new ind can tomorrow and try that.....the fuse has already been changed to a blade type before i got the bike. We'll see eh...Cheers again, Chris.

[catteeclan]

Check the plug to the reg/rec. Red wire has a habit of corroding.

[CHRISZZR600]

Thanks catteeclan....I've checked everything i know how to and still no joy..starts first kick but battery voltage drops like a stone from 12.5 volts to 11.4 volts in about 2 mins. The battery itself seems fine.....does anyone know how i can test the reg/rect unit off the bike??? Thanks for all your suggestions guys...no joy yet..but i'm still hopeful.!! Chris.

[416cc]

The ignition runs from a seperate setup from the alternator housing, which is why the bike will kickstart despite the battery being flat/partially discharged/fully charged.

If you have a multi-meter then check the AC voltage emerging from the alternator via the yellow wires. If there are more than two wires ie. three yellows, then you can measure across any two wires & you may well get about 15vac if it's a 12vdc system, or about 8-9vac if it's a 6vdc system.

It's a little more difficult to check the regulator if it's off the bike. With the engine running & it's known that the AC volts from the alternator is ok, then check the DC voltage across the battery. If when you rev the engine it goes up to a lot more ie. 18vdc on a 12vdc system & it varies quite a bit with the revs, then it's the regulator. If the DC volts are a lot less than say 12vdc when you rev the engine, say only 9vdc if any at all, then it's more likely to be the rectifier. If it's a combined unit, then the best answer is these people...
Electrical parts > Honda MX Motorcycles - stator generator regulator rectifier