Charging issue! Help please

[Wenman]

Hi everyone,

Just a quick one I'm in the process of testing all the components involved in charging the battery, reg/rec, stator field coils, rotar etc

When testing the resistance in the stator field coil it reads 1.3ohms minus the resistance between the probes (0.4ohms) This would make 0.9 ohms!!
Manual states .35ohms plus or minus 10% therefore if I am correct the maximum resistance should be 0.39 ohms and my readings are all 0.9 ohms!!

Can anyone tell me if my readings would mean the coil is knackered or will it just not charge properly??
I can't seem to find anything else wrong with the system at present!!

Thanks

Alan

[Bryanj]

Never had a coil go duff, bad charging is dirty connectors oor regulator not working normaly , possibly rectifier

[mike the bike]

The low resistance of coils make testing a bit unreliable.   As Brian says, they don't usually go faulty.   It's more likely to be the rectifier,  followed by the regulator.  Also check continuity between the phases.  ie; yellow 1 to yellow2,  yellow1 to yellow3,  yellow 2 to yellow 3.  They should all read roughly the same.

[Wenman]

Hmmm interesting,

I've tested the combined reg/rec I purchased which is fine although I have always questioned if it was the correct combined reg/Rex for my bike. I will post a pic of it soon.
It has..
3x yellow
1x red
1x green

I believe these plug straight j to the harness and seem to match up colour wise.

It also has 1 x black/red stripe wire which forks into 2 spade connectors. The fitting instructions state to place these spade connectors, one into the black wire of the old regulator and the other into the white wire if the old regulator and discard the green wire from the old regulator?
It just doesn't seem right to me??

The thoughts of your minds in this one would be very appreciated!!

Thanks again
Alan

[totty]

That type of reg/rec and that wiring of it is correct. (although I reverted to standard after having one of these regulate the voltage too low)

Have you tested the system as a whole? What voltage to you get at the battery with the engine at say 3k rpm?

[Wenman]

Here's a pic!

[Colonial-Clive (yindi)]

I have just had this same problem, it was a spade connector that had pushed out of the block on the back of the panel!

[Wenman]

Thanks Clive, sadly all my connectors are in tact! 😩

Has anyone else successfully used a David Silver Spares  combined reg/rec?
Be interested to know if I'm wiring it up right?

Also noticed I'm blowing the main 15amp fuse!!
With everything connected up right except the reg/rec, turn ignition on fuses stay in tact.. when connecting the main block connector for the reg/rec, turn ignition on, fuses stay in tact, as soon as I connect that black/red wire to the black and white of the old regulator fuse blows!

This is becoming very annoying!!

Alan

[Bryanj]

Sounds like either the instructions are wrong or the reg/rec is duff

[Wenman]

Thanks Bryan,

I've tested the reg/rec with a multimeter and as far as I can see it's operating as it should!
This lends it to the wiring.. be odd coming from such a reputable dealer such as DSS for it to have incorrect instructions!

Alan

[Bryanj]

You cant test the reg with a multimeter, only on load

[flatfour]

I've used the DS combined regulator/rectifier without problems. I fitted it to my CB750 for a while late last year, as I was concerned that the original system was overcharging and I was using an AGM battery. It all worked well enough, however after having the original regulator and regulator bench tested, I refitted them for originality.

I also temporarily fitted the DS unit to my CB500 whilst I had the regulator and rectifier on that bench tested (not because of concerns in the case of that bike, simply because having found someone who could do the tests I thought that I would have both bikes checked, mindful of the age of the equipment).

The DS unit is packed away now, but I will not hesitate to use it on either bike if needed.

[Wenman]

Thanks flat four!

Can you remember how you wired it up? Did it matter which of the spade connectors went to the black and white wires  from the old regulator??

Thanks
Alan

[flatfour]

Although I can't remember how I wired it, as I still have the item in its box with the instruction sheet, I'll have a look and let you know. I did no more than follow the instructions given by the maker when I fitted it and, as mentioned earlier, all was fine.

[flatfour]

This is summarised from the instruction leaflet and is how I wired the single unit (note: I am no electrician, so if you use these notes, you do so at your own risk!).

1) Remove original Rectifier and its wiring from the block connector
2) Fit new Rectifier/Regulator and plug block connector into harness
3) Remove white and black wires from original Regulator and wrap terminals that they were fitted to on the Rectifier with tape
4) Connect one terminal of black and red wire from new Rectifier/Regulator to the white wire and the other to the black wire
5) Leave the green wire on the original Regulator and leave this component fitted to the bike (it acts as an earth)
6) Start engine and check charge voltage (original test data shows 14.7 - 15.1 V). The target range was 15 V for these tests.