Guides Checking a charging system

How to troubleshoot a charging system.

Okay, before I start, there's a few things that you guys need to know. First is that I'm expecting that you have a general knowledge of how electricity works. If all you know for electricity is how to change the remote control batteries, then don't even attempt this. Just take it to the shop. Second is you need to have at least a digital multimeter with ADC, VDC, VAC, Resistance, and a Diode setting.


First start out with 5 tests to verify that there is indeed a charging system problem.

1. Battery Voltage. - Key off: between 12 - 13VDC.
2. Key off Amp Draw - At the main fuse: < (less than) 1ADC
3. Key on Amp Draw - At the main fuse: Results will vary because of different loads.
*Note - DO NOT START THE BIKE WITH YOUR METER IN PLACE OF THE MAIN FUSE! Also, if you can not acces the main fuse, put your postive meter lead on the red wire at the solenoid, and put your negative meter lead on the positive battery lead. This way you will be able to get your amperage readings AND let you start the bike without blowing your fuse.* Charging amperage should be at least 1 ADC
4. Break even speed - The RPM in which the charging voltage at the battery turns positive - Should be before Idle
5. Charging voltage at the battery - Between 13 - 15 VDC.
6. Max charging RPM. - There should be an RPM where your bike's charging voltage plateau's off. Usually its around like 4k RPM. If it doesn't, then replace your regulator/rectifier immediately.

Number 5 is basically going to be your deciding test. The numbers there, could vary, but it needs to be higher than your result for number 1. If its not, then you have a charging system problem, if it is and your battery won't stay charged, then you either have an unwanted draw from somewhere, or your battery is bad. So lets say that your bike isn't charging. Here's where we go from here.

Stator check - The 3 yellow or white wires all together. Unplug them, and turn the bike on. Go 1 to 2, 1 to 3 and 2 to 3 with your leads, and all of your reults should be within about 25% of each other on VAC. EMS should be done with it plugged in. Next turn the bike off, and with the stator still unplugged, do an IB test on it. On Ohms, Each lead to ground. All should be OFL. If you get anything, then you probably have a bad stator. Next do an resistance test. Again, test all 3 like you did before, and you should get between .2 and 2.5 ohms for each. If you get one that is WAY WAY off in left field for any of the tests, then you probably have a bad stator.

Regulator/Rectifier - That's the little box that has the fins on it that the stator connects to. Put your meter on the Diode setting, and unplug the rectifier. There's gonna be 5 wires comming out of the Reg/Rec: the 3 to the stator, and a red one and a ground wire. To do the diode tests, put your red lead on the red wire. Then go to the 3 that plug into the stator. 1,2,3 tests, then switch your meter leads and do the same thing. You should have OL for one of the ways, and a small voltage for the other. Then move to the ground wire, and do the same tests, switch leads again and test again. You should have 12 tests total because of the 6 diodes in there. For each of the red and ground wires, you should have OL for 3 of the tests, and a small voltage for the other 3, like I just said. If all that checks out, then your rectifier is good. Next plug everything back in, and check your ground wire connection from the Rec/rec. Make sure you check it as close to the reg/rec body as you can, cuz there could be a break in the wire or something. If there's an open, then locate it, and repair as necessary. Do the same with the red wire to the batter positive terminal, as that's where that one goes.
If everything checks out good, then you either missed something, have a bad connection somewhere, or have a bad regulator. You should be able to detect the bad regulator from one of the tests that you did at the very start.
Save some money and do your own checks, you might just find the problem that the bike shop is going to charge £££ :thumbup

YOU DO THIS AT YOUR OWN RISK AND NOT MINE :roll

Great post...added to my favourites :thumbup

So how do i change these batteries in my remote ????




a great post.very helpful

I do have a work flow pdf document that makes it easier to understand if anyone wants it.
Tried to upload it into the file vault but it wont let me :dunno

As many of you may have found out, we cannot simply remove the stock bulbs and replace them with LED indicators. The usual fix is to install load resistors in parallel with the LED’s. The problem stems from the fact that Aprilia elected to use a single turn indicator lamp.