Generator test

[Snapey]

Battery problems today on K5 showed no charge at the battery. The manual says remove sprocket cover, undo plug & check OHMS reading between the 3 yellow wires, should be .2 to 1.0.

Now for the questions;- What number should the meter be set 20,200 or 2000? I set mine at 200 & got readings of 1.2 (good or bad?)

Volts ... should be 60v @ 5000rpm. Mine shows about 3 but this I'm not understanding. 60V? I'd have thought it should show 13 or 14 volts. Because I don't get a reading does this mean the stator is stuffed?

Is there a stator test once I've got it out? I don't want to buy a new one & find the problem is something else.

[KiwiCol]

I've not been there Snapey, can't help.   I'd say the rectifier would reduce & correct that voltage to something the bike can use though.  Think it starts out as AC & gets converted to DC.

Make sure you're using the AC range though, using DC range on AC circuits gives erroneous readings - so I've found out.

[grog]

Snapey, i have an auto electrician mate, can ask on Monday if you want.

[Hooli]

Slightly high Ohms could just be manky contacts increasing the resistance. The ranges on your meter just make it more accurate, provided it's not set below what you're trying to read it'll be close enough. If you get the same between all three wires I wouldn't worry about it it sounds close enough to me.

As Col says you need to test in AC before the reg/rec.

When my stator burnt out I didn't get a reading off one of the yellow wires, as it's a three phase generator & one phase had failed on mine. When I took it out it was obviously burnt. Enjoy getting the cover off/on as it snaps into place due to magnetism & can bite your fingers. Plus it'll probably pull the starter cog out & you need to rotate the engine slightly to get it back in place.


The manual lists how to test the reg/rec too. I'd start there as they are known to fail on a lot of bikes & being where it is (near the swing arm pivot) you can collect a lot of shite around the connectors so they rot.

[Snapey]

Snapey, i have an auto electrician mate, can ask on Monday if you want.

Thanks Grog I'm interested in what he says although Hooli covered it pretty well in the next post.

[Snapey]

Good explanation Hooli but I'm still confused with the voltage reading from the generator although my knowledge of reading a multi meter is very limited.

Ah yes ... the generator cover ... been there, done that.

Reg/rec will be tested tomorrow.

[Mick_J]

The o/p from the generator is AC so 60v is correct but it has to be converted into DC for the bike to work correctly.  Very basically the regulator/rectifier does this by chopping the voltage in half and inverting the bottom (-) half, then it clips the top off the 30v peaks and smooths it out to about 15v and then puts it into the battery circuit which is why a charging battery usually has about 14.5v on it.  Hope this helps.

[Snapey]

The manual tells me to do a diode test but the meter has to be reading 1.4. My el-cheapo Dick Smith special is showing 1. I'm getting readings between the terminals but they're in the hundreds instead of maybe 0.4 to 0.7. So do I buy a decent multi meter of go to an auto electrician?

The readings between the yellow wires of the generator all read 1.2 ohms & that's on AC. What does the symbol that looks like a laying down 8 & then the ohms symbol mean? Imagine the figure 8 tilted 90 degrees.

[Hooli]

An '8' on it's side represents infinity. It's normally just a connectivity test setting rather than registering a reading. If that makes sense?

As to your readings, you might just be on the wrong scale. If you're reading Ohms & the manual is in hundreds of Ohms for example 100Ohms on a meter set to 100s would show as 1.0. Provided you know & 'translate' it then it doesn't matter.

[KiwiCol]

I thought it was a lazy 8, too tired to stand up straight 

[Irish in Oz]

Didn't you have problems with the rectifier before!

[Snapey]

Didn't you have problems with the rectifier before!

Sure did Jeff ... five years ago. Only $147.50 for a new one. It's a shame Mr Suzuki didn't put it in the same place as the Katana. If they couldn't do that why not put the bloody thing in a pocket inside the battery box similar to where the ECU is.

[Hooli]

Can't hide them in the battery box as they get rather hot in use. Hence hondas are famous for them failing as they hid them inside the bodywork for a while.

[seth]

If your in a hot country
or your reg/rec is getting hotter than you'd like top tip is to fit a 12v case fan from a computer to the cooling find on the reg/rec.
Wire it to a switched live and it'll keep everything nice and cool.

[Mister Fishfinger]

The manual tells me to do a diode test but the meter has to be reading 1.4. My el-cheapo Dick Smith special is showing 1. I'm getting readings between the terminals but they're in the hundreds instead of maybe 0.4 to 0.7. So do I buy a decent multi meter of go to an auto electrician?

The readings between the yellow wires of the generator all read 1.2 ohms & that's on AC. What does the symbol that looks like a laying down 8 & then the ohms symbol mean? Imagine the figure 8 tilted 90 degrees.

Hello Snapey. To test a diode properly you can't use a meter on its resistance setting. That only works on conductors, i.e. something that follows Ohm's law.

Diodes are semiconductors. Connected up one way they don't pass any current at all, but if they are connected the other way they will pass a current - but only when there's a little bit of voltage to get the electrons moving. Typically this is 0.7V or thereabouts for a regular silicon diode, after which the voltage stays pretty much at 0.7V even as the current increases dramatically.

So you need to look on your meter for a setting that has a diode symbol, it's a triangle with a bar on one end. If your meter doesn't have that you can pick them up dirt cheap on Amazon or eBay these days.

I haven't looked it up in the manual but if it's specifying 1.4V then maybe that's 2 diodes in series, hence 2 lots of 0.7V.

Hope that helps.