Electrical Guru needed!

[pappas]

I've been pulling my hair out trying to sort out the charging system on my WR450!

Last ride I went on the starter was working fine until we stopped for lunch, got back on the bike and nothing! Not even the LED on the ignition button was working.

I've got the bike home and the battery (new) is dead flat, 0 volts. Once the bike is started the voltage at the battery is at 8 volts where the manual says it should be approx 14 volts.

I bought a new rectifier / regulator and still got the same voltage reading?

So my question is does the regulator require the battery to have some charge in it for it to start charging? Or do I have a proplem with the stator?

[Hillsy]

Sounds like your battery just shit itself. Put it on a charger and see if it holds a charge. Batteries in good condition should be around 12.8V at rest.

[Docktor]

try disconnecting the battery and see if it still runs..... it should be able to run off the reg. at idle around 13 is ok, anything up to 14.8 at around 4000 ripms. if not , maybe the rectifier is dead ? . i know ya said u got a new one but.....

[fimpBIKES]

is there voltage coming back from the stator?

[pappas]

The Battery is dead flat so the bike is running directly off the regulator. I haven't checked the voltage from the stator, that's next on my list to do.

Main thing I wanted to know is if anyone knows if the regulator will only give charging power to the battery if it senses a voltage from the battery? If that makes any sense.

e.g. If the regulator senses that there is no battery attached it supplies only enough power to run the CDI/ignition lights etc. but if there is a battery it will supply power to charge the battery as well.

[scotty]

If you put a set of jumper leads to the terminals it should be running at round 13-14 volts. it sounds like the stator is fooked.if it runs 8 volts at idle with a new reg/rec then yes it is stator.

[grindella]

what you have described is stator, check first to see if any wires are broken on the stator assembly. Check resistances on the stator make sure all windings are equal

[fimpBIKES]

pretty sure reg/rec units arent that smart
unstable stuff goes in, usable stuff comes out

[pappas]

I was thinking it could be done with a zener diode, which could open the circuit once it got voltage in from the battery.

Didn't get to check the stator last night so will have to wait till tonight.

[angrypom]

usually a vehicle does need a reference voltage for the regulator to work correctly also the rectifier may have exciter diodes to induce a voltage in to the stator. i would start with the basics check you have no blown fuses and have continuaty between the battery and charging system.

[livewire]

My first thoughts would be to check the battery first.
Have you charged it externally and then checked it?
You say it's new, what was wrong previously?
Same fault would suggest not the battery, but.
Also agree with the checking of basics first, before getting too excited.
Workshop manual will give accurate testing proceedure and measurement, and a wiring diagram/colours is always handy.
Good luck!
PS Cammy9r's sticky in the subject listing "OE pdf manuals" might be handy? Seen your bike model listed.

[Mishdog20]

Mate, i had the same probs on my R6, when the bike was idling, it only showed less than 12 volts on the multimeter which gradually crept down until the electric fuel pump cut out at about 8 volts. It turned out it had a fucked regulator and stator. If there is less than 13 volts showing on your multimeter when the bike is idling, it has to be one of the above 2 items.

[pappas]

Ok, so I've fixed the problem. Took the battery out and charged it for 4 hours. Still had no charge!! So went and got another new battery and what do you know! Bike is now producing 13.4 volts at the battery.

I took the bike out to Lithgow over the weekend, did over 200km without a hitch! Bike started with the button every time! So I guess the reg/rec needs a voltage from the battery to work properly (at least on my bike). Thanks for your help!

[Hillsy]

Glad I could help ;)

[pappas]

You did pick it from the start mate!! Nice one!

[Mishdog20]

Well what do ya know, thats bloody suprising mate. Its just good to know that ya sorted the problem out once and for all.