500K2 Electrical Connection Blocks

[philward]

Just dummy fitting new harness and having a mental block on the electrical connection blocks on the mounting bracket under the LH side panel.
Top connection is from the loom, middle from alternator/nuetral/oil presure sub loom - but what goes into the bottom connection block?

[philward]

Sorted and mental block dislodged! Obviously rectifier but god knows where it is - remember testing it and repainting

[philward]

I can't seem to locate the rectifier off the 500 (I refurbed and bagged up all the electrical components about 4 months ago - I am sure I remember repainting and cleaning the wires on the rectifier but can't find it now). I've got a spare from the 750 that I am sure I had to change because of a charging issue on the k6 cafe racer I built.
So I've tried to test it using the diode setting on my multimeter.
I'm testing across the green to each yellow lead with black multimeter lead on green and red lead on each yellow wire on rectifier connection block - I'm getting a reading of '592' on each yellow and if I reverse the multimeter leads, I get the same reading. This doesn't seem right getting the same readings!
Am I testing it correctly?

[philward]

I thought the middle block on the K0 was round pins?

Also check the fuse wire, it looks to me to be showing signs of melting in the past.

Not sure what you mean about round pin on K0 Kens? Mine's a K2. Will check the fuse wire

[Bryanj]

Ken only the early K0 had the round pin blocks.

[philward]

I thought it was all of them Bryan, odd that Honda would change it mid run so to speak

Oh my mistake, I thought Paul’s was a K0 for some reason.

Have you started on the Christmas Port early Ken? Wrong model, wrong person (Paul>)!
Any guidance on testing the rectifier?

[philward]

Found a post from Mike explaining test process

[philward]

Followed Mikes advice as follows (with rectifier completely disconnected)

'Establish which is positive of the rectifier and which is negative.
Using a multimeter on the diode range (or ohms range if there's no diode range)
Put the red meter lead on the negative and test each yellow lead of the rectifier in turn.  Then do the same tests with the black meter lead on the negative.
You should have a reading on all 3 in one direction but no reading the other direction.
Now put the black lead on the positive,  check all 3 yellows .
Do same with the red lead on the positive.
As before,  a reading in one direction but nowt the other direction.'

However, I get a reading (diode range) when putting red meter lead on neg on rectifier AND with black lead on rectifier negative
I get nothing when putting black meter lead on postive or the negative rectifier lead?

[Bryanj]

Hey changed cos the spades make better contact and dont melt as easy

[mike the bike]

  However, I get a reading (diode range) when putting red meter lead on neg on rectifier AND with black lead on rectifier negative
I get nothing when putting black meter lead on postive or the negative rectifier lead?

That's as it should be.  You're measuring through all six diodes in one go.

[Moorey]

  However, I get a reading (diode range) when putting red meter lead on neg on rectifier AND with black lead on rectifier negative
I get nothing when putting black meter lead on postive or the negative rectifier lead?

That's as it should be.  You're measuring through all six diodes in one go.

 On the countdown now Mike.

[mike the bike]

Wot?

[philward]

Thanks Mike - this one came off the K6 project when it wasn't charging - changing for a spare cured the problem but if this one is checking out ok, it was maybe just a dirty connection that was cured when the alternative rectifierwas plugged in.
Anyway, its a result that this ones working (still don't know were I have put the original 500k2 rectifier though - too many spares for too many bikes!)
Thanks again

[mike the bike]

Don't rely on testing all six diodes at once (positive to negative).
The worst case scenario is four of the diodes are duff and you're only reading through a pair of diodes connected to one phase.  In that case, you'll get charging but not a lot. 
Certainly not enough to have any lights on.

[philward]

Haven't tested pos to neg Mike - tested as per your recommended way but
'I get a reading (diode range) when putting red meter lead on neg on rectifier AND with black lead on rectifier negative
I get nothing when putting black meter lead on postive or the negative rectifier lead?'
Am I missing something in my ignorance?