Battery not charging - help please

[alexibrow]

My Version R broke down the other day, first time since I bought the bike 6000 miles ago. It cut out at a junction and the engine wouldn't turn over, just some clicks from the starter solenoid - classic sign of a flat battery.

Checked the batery with a meter - around 9.5 volts. Jump started it and took another reading - at around 4000 rpm, it read roughly 10.5 volts.

I've replaced the battery with a shiny new one, which reads 12.5 volts. With the engine running at 4000 rpm, I'm getting just under 12.4 volts.

So there's a fault in the charging system. As the reg/rec is the usual suspect, I'd like to fault-find it. Does anyone know how to do this without replacing it with a known good one (as I don't have a spare)?

I'd also like to check the generator output; how do I do that?

I'd be grateful for any help on this one.

Cheers,
Alex.

[meno]

hi m8, i think it should read about 14 ish with engine running but as far as testing it beyond that im pretty unsure tbh... hope you get it sorted buddy.

[alexibrow]

Found this link to a faultfinding flow chart on ye olde forum:

http://www.electrosport.com/technical-r ... -guide.php

It's a step-by-step guide to faultfinding charging circuit problems, and checks the regulator/rectifier and connections, and the generqator output etc.

Will give it a try over the next couple of days and post the results here.

Meno - you're right, a healthy charging system should put out a max voltage at the battery of around 14.5volts.

[wullvfr]

obviously when you start the bike and rev it to 4000rpm the volts are dropping.....so the battery is getting drained instead of charged.that definately sounds as if the reg rec has packed up.
to test the alternator disconnect the block connector that comes from the alterntor and with the engine running check the voltage output by using a multimeter......switch it to ac volts and take three readings,they should all read 50 volts or above and if any are below or different then the stator windings are faulty :D :D

[superfourben]

Go through the fault finder very mythodically noting voltages etc as you go and you will more than likely find the fault, have used it a couple of times myself and got to the cause, both times being reg/rec.... good luck :)

[alexibrow]

Thanks for the tips so far, they're much appreciated!

I've booked the afternoon off work tomorrow to get stuck into it, so hopefully with your help, the flow chart and a couple of beers I should be sweet!

Thanks again.
Alex.

[meno]

lol alex now ive fixed my ignition switch its decided it likes running on 3 ...it must be 400sf jinx week

[alexibrow]

to test the alternator disconnect the block connector that comes from the alterntor

The only block connector I can find is the one going into the reg/rec, with three yellow wires, a red wire and a green wire. Is this the one? If so, do I take ACV readings for the three yellow wires?

The faultfinding chart says to measure the resistance across the other two, and mine is open circuit meaning that the generator is suspect.

I've also taken some measurements across the reg/rec terminals as the manual states (english translation from Russian) and they're all wrong, so either the reg/rec is suspect also or I'm doing something wrong!

[alexibrow]

OK, I found the block connector for the generator hiding next to the fuse box. Measuring across the three yellow wires I get 25V AC for each pair. Measuring the resistance across each pair, ie the resistance of the windings, I get around 0.1 ohms, which is within the manufacturer's limits.

If the windings are OK, could it be something mechanical inside the generator? I need to take it apart to find out; is there an easy way of doing this without dropping the oil out and taking the entire side covering off?

[alexibrow]

Latest update: I've learnt over the years to double check measurements, so I double checked the output from the generator. Sure enough, at idle the output was between 12.5V and 25V AC, but when revved to 5000 rpm, it shot up to 50V which is correct.

Luckily I hadn't started to strip the generator out, although I had all the tools and the oil pan ready!

I've cleaned a couple of connectors and I checked the resistances across the reg/rec pins again and the readings are at odds with those in the manual, so now I'm sure it's the reg/rec that's gone down - I don't think it can be anything else! I've ordered a new one from Germany for £40, and once it's fitted I'll check to see if the battery's charging again and post the results here.

Thanks again for all your help! :D