Testing Sherco Electrics

[howard]

Hi to all you electrical boffins,

I'd like to know how to test the diode, regulator, coil and stator( both in the bike and isolated) in the Sherco trials bikes, and what measurements should I get if the components are normal or failed. Please give as much detail as possible. Also, could someone post a wiring diagram please. If any of you know exactly what each component does, please inform me.

[copemech]

Hi to all you electrical boffins,

I'd like to know how to test the diode, regulator, coil and stator( both in the bike and isolated) in the Sherco trials bikes, and what measurements should I get if the components are normal or failed. Please give as much detail as possible. Also, could someone post a wiring diagram please. If any of you know exactly what each component does, please inform me.

please move to the Sherco threads

[trialsnutterman]

Testing the stator

Using the diode test on a multi meter to test the trigger

Blue no reading

brown 1601

black 1626

using the red lead and black on earth

Blue 725

brown 766

black 767

using the black lead and red on earth

I also tested the resistance's of the other wires

White to red 95.4 ohms

Red to green 549 ohms

green to white 637 ohms

Hope this helps

[copemech]

Well as noone has managed to move this thread to a proper location, I shall make an attempt.

Firstly, you want to know a lot of information in a drip of response! This is not going to happen, as the operational theory of each circuit is not that easily explained.

Secondly, I have no friggin idea even what year bike we are attempting to address, no less why? they do differ!

Thirdly, some of this is considered "dark art" and noone will tell! Probably because your static testing will yield no result that matter! Static testing makes little difference in the function of certain devices installed.

[copemech]

Ok, now that we are on the right thread at least, I will attempt to do a short operational description on your little Yellow wire! It is the one coming up from the stator that powers everything else BUT the ignition on the later Leonelli ignitions and also very similar to the earlier Ducati systems. This is connected to the source coil that runs the fan and lights and horn and such.

With this wire disconnected, the ohm spec through the generating coil to ground(earth) is around 1 ohm according to spec. This coil circuit generates an AC voltage when running that varies with rpm. As things like light bulbs and horns really do not care fore the most part, they will function with AC voltage, they may get brighter or dimmer, but there are still operational limits to their design, so a voltage regulator is connected to this output in order to essentially shunt off all excess voltage back to earth at higher rpm's. And that is what it does at around 12V-14V.

As we are on watercooled bikes, we need a fan to move some air and keep things in the motor when we are not moving fast enough to keep things cool by natural airflow past the radiator like a MX bike. So we need these little high output motors that happen to run on 12V DC power. In order to make our system power into something that the DC motor can use, we have to convert it. This is what the rectifier does which essentially chops the incoming AC waveform poperly in half, only letting the usable portion through and shunting the rest to earth so the fan motor can use the remainder.(notice a poor earth on a regulator can fail your fan).

If you add a little thermo switch in your fan circuit, it should turn on and off properly! Your lights should be fairly stable and you can ride happy! All off one wire and two little widgets with a switch!

Edited May 24, 2009 by copemech