Hello to all,

So what is it about the factory rectifier and zener diode?
It seems to be a matter of course that these items are replaced when doing ay electrical rehab on a Commando.
Why?
I
As an electrician I understand the concept of their operation and see no reason they aren't capable of doing the job.
Back in the day was the rectifier found to regularly crap out? Did Zeners fail at regular intervals keeping riders from getting to the watering hole?
If they are junk for a reason then I'll build a wiring scheme on XBSKT 2 without them.
If they have a bad reputation due to poor understanding and bad connections in the past perhaps I'll go ahead and use one of the rectifiers and Zeners that have piled up on the "electrical" shelf.
If I had to guess the rectifier is fine if connected correctly. It's really a basic design but maybe you all and history can enlighten me.
Honestly, I'd rather spend the budget on nice wheels.;]

Have a good day,

Jeff

Nothing wrong with them as-is.

Jeff,
I am running the original gear, but I find the battery does overcharge and looses electroloyte on longer runs. I am contemplating a Boyer powerbox in the future, to fix the charging and also I believe I can get a unit to activate the charging light. So this takes out the dodgy assimilator, that has never worked.

So yes you can use the originals, but keep an eye on the battery?

Cheers Richard

xbskt wrote:So what is it about the factory rectifier and zener diode?
It seems to be a matter of course that these items are replaced when doing ay electrical rehab on a Commando.
Why?

Because they could be 40 years old?

There's nothing basically wrong with the original rectifier - except that it can be easily damaged. It is a silicone diode rectifier (not the less reliable selenium type that some people appear to think it is).

I'm running the originals as well. Charges fine even when always riding with the headlamp on (local law). I do admit to using a battery tender occasionally in cold months.

If they are within specs when checked with a decent meter, they will be just fine.

MAKE SURE TO HAVE A FULLY INTACT BATTERY VENT DRAIN TUBE, AND ROUTE IT CLEAR OF THE BIKE SO YOU DON'T TRASH YOUR EXHAUST AND/OR OTHER BIKE PARTS WITH ACID RESIDUE.

L.A.B. wrote:

xbskt wrote:So what is it about the factory rectifier and zener diode?
It seems to be a matter of course that these items are replaced when doing ay electrical rehab on a Commando.
Why?

Because they could be 40 years old?

There's nothing basically wrong with the original rectifier - except that it can be easily damaged. It is a silicone diode rectifier (not the less reliable selenium type that some people appear to think it is).

Hi Jeff
+1 on that they can be easily damaged. If the rectifier body twists you damage it. If you over torque the zener or if it is not grounded properly then you may have issues.
Regards,
CNN

I seem to remember a diode on my original rectifier going open circuit when it was about ten years old and I replaced it with the solid state unit that's still on there. The twin zeners on my MkIII have been replaced once because they were looking a bit corroded and tatty but they still worked fine. They sit on nice big heat sinks and I've never had trouble with them. I see no reason to change.

The whole charging system is much more reliable than most Japanese bikes of the same era. I really don't know where the bad name came from.

A reason for change is less clutter and less wires .
For all the years I used them , the original setup gave me less trouble than the Boyer power boxes ( 3 in the 3 years I used them) .
IMO , the integrated cap is the culprit .
Podtronics are troublefree (touch wood .)

GP : a battery with a vent tube ??
Can"t remember the day I"ve seen one of those ..

ludwig wrote:GP : a battery with a vent tube ??
Can"t remember the day I"ve seen one of those ..

I can't remember ever seeing a wet lead-acid motorcycle battery that did not have a vent for a tube?

I'm fitting a solid state unit with my new Sparx alternator today just because it came with the Alternator & my old one is a bit worn. Still not sure what will happen to my asimilator light. If it just won't come on, or will stay on etc. I'm wiring the alt/reg directly to the battery through fuses.

You don't see a whole lot of "survivor" britbikes without acid stains on the pipes due to bad routing of the battery vent tubes.

L.A.B. wrote:..I can't remember ever seeing a wet lead-acid motorcycle battery that did not have a vent for a tube?

I can't remember that either .
Only , I can't remember the day I've seen one of those .
The last time I fitted a battery with a vent tube was ..mm ..can't remember ..

I'm using the originals and they work fine...but also wired in an LED voltage monitor so if they die I'll know right away voltage-monitor-demo-video-t7576.html
have heard of batteries boiling when the zener fails. Electrolytic capacitors often go bad with age, but the rectifier and zener diode should not

ludwig wrote:

L.A.B. wrote:..I can't remember ever seeing a wet lead-acid motorcycle battery that did not have a vent for a tube?

I can't remember that either .
Only , I can't remember the day I've seen one of those .
The last time I fitted a bettery with a vent tube was ..mm ..can't remember ..

What can you remember?