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Main fuse/Positive ground problems

Classic Norton Commando Motorcycles.

Re: Main fuse/Positive ground problems

Postby Supercat » Mon Sep 04, 2017 2:26 pm

Is there some way I can connect it to one set and/or the other and test things without trying to start it or connect the battery? Can I just leave the multimeter setup as I have it (to the main leads), and turn through the key switches? Would this be safe? It was definitely connected to one of these two sets before. And I'm 99% sure it was the white and purple set.

Also, I assume I can run this without the zener connected, if I just have the light on - is this correct?

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Re: Main fuse/Positive ground problems

Postby L.A.B. » Mon Sep 04, 2017 2:56 pm

Supercat wrote: Is there some way I can connect it to one set and/or the other and test things without trying to start it or connect the battery?
Can I just leave the multimeter setup as I have it (to the main leads), and turn through the key switches? Would this be safe?


Various alternative suggestions have already been given, such as, use a low wattage bulb in place of the fuse, or you could connect your meter set to amps (or milliamps ignition off) between the fuse terminals.


Supercat wrote: It was definitely connected to one of these two sets before. And I'm 99% sure it was the white and purple set.


I don't recommend you reconnect the Boyer white to any white/purple wire as the WP wiring is effectively redundant once the points ignition has been replaced with EI.

Supercat wrote:Also, I assume I can run this without the zener connected, if I just have the light on - is this correct?


Not wise, at least not for long periods and you'd probably have to limit the revs (to about 3000 RPM?) once the battery was fully charged. If the system voltage is allowed to exceed 16V for any length of time then the Boyer box can be damaged.
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Re: Main fuse/Positive ground problems

Postby Supercat » Mon Sep 04, 2017 3:20 pm

L.A.B. wrote:Various alternative suggestions have already been given, such as, use a low wattage bulb in place of the fuse, or you could connect your meter set to amps (or milliamps ignition off) between the fuse terminals.


This was for finding a short. My question was about connecting the white boyer wire to the wires it was previously connected to and seeing if I would get a different reading with the ignition switch in the on position, with no battery connected. It's possible the previous owner might have changed some of the wiring.

L.A.B. wrote:I don't recommend you reconnect the Boyer white to any white/purple wire as the WP wiring is effectively redundant once the points ignition has been replaced with EI.


Will it hurt it to connect the Boyer white and the white purple for the test described above? I'm not going to try it if there is any risk.

L.A.B. wrote:Not wise, at least not for long periods and you'd probably have to limit the revs (to about 3000 RPM?) once the battery was fully charged. If the system voltage is allowed to exceed 16V for any length of time then the Boyer box can be damaged.


Got it. Is there any fixing a zener diode, or do I just need to order one? Thanks L.A.B.

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Re: Main fuse/Positive ground problems

Postby L.A.B. » Mon Sep 04, 2017 4:02 pm

Supercat wrote:
L.A.B. wrote:Various alternative suggestions have already been given, such as, use a low wattage bulb in place of the fuse, or you could connect your meter set to amps (or milliamps ignition off) between the fuse terminals.


This was for finding a short. My question was about connecting the white boyer wire to the wires it was previously connected to and seeing if I would get a different reading with the ignition switch in the on position, with no battery connected.


Supercat wrote:Will it hurt it to connect the Boyer white and the white purple for the test described above? I'm not going to try it if there is any risk.


I suppose you could -as a test.


Supercat wrote:It's possible the previous owner might have changed some of the wiring.


It's possible, so we can only go by your description of what's there when compared with the original wiring diagram but if it's at all possible to connect the Boyer white directly to the power supply white (so without the kill button) then there's no logical reason to include any other unnecessary extra wiring.


Supercat wrote:
L.A.B. wrote:Not wise, at least not for long periods and you'd probably have to limit the revs (to about 3000 RPM?) once the battery was fully charged. If the system voltage is allowed to exceed 16V for any length of time then the Boyer box can be damaged.


Got it. Is there any fixing a zener diode, or do I just need to order one?


Yes, or, fit a modern regulator/rectifier (reg/rec box) such as Podtronics in place of the Zener and rectifier.

https://www.classicbritishspares.com/bl ... -rectifier
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Re: Main fuse/Positive ground problems

Postby Supercat » Mon Sep 04, 2017 4:40 pm

Wicked, thanks for the help, and for the link! The two in one Podtronics unit looks pretty great, and it looks like there are options that would allow for running with no battery with a Boyer setup. That's awesome.

I tried that test I described in the last message and there was no change to the readings with the Boyer wire connected to the white-purple. I'm not sure what this means, if anything.

But hold on one sec... here is step 19 from the Boyer instructions:

"19) Connect the white-blue wire (the one removed from the ballast resistor) to the white wire from the transistor box".

Are you sure I'm not meant to be connecting the white-purple wire that the PO appears to have used to the white Boyer box wire?

And one more question - if I am able to get spark using the actual wiring instead of the bipass, am I better off running it like that if I wanted to make short trips around town (like less than 5 km at a time), or would I be better of just using the bipass setup while waiting for the new part to arrive?

Thanks again!!

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Re: Main fuse/Positive ground problems

Postby phsDommie » Mon Sep 04, 2017 7:31 pm

Hi Supercat,
I read some, but not all, of the thread here, so if you have already found the source of the short circuit, forgive me. I had an exasperating short in my "74 Commando that blew innumerable fuses until I found it. The wires connecting to my rear brake switch were behind (and out of sight of) the left exhaust and were intermittently touching the hot exhaust. The insulation was melted away and the bare wire touched the exhaust.
Paul.

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Re: Main fuse/Positive ground problems

Postby L.A.B. » Tue Sep 05, 2017 1:06 am

Supercat wrote:But hold on one sec... here is step 19 from the Boyer instructions:

"19) Connect the white-blue wire (the one removed from the ballast resistor) to the white wire from the transistor box".


It does, and you could connect to white/blue, but once again, the white/blue is basically a redundant wire once the ballast resistor has been disconnected/removed, so it makes more sense to connect Boyer white to white/yellow (also shown on the Boyer diagram) at the main junction under the fuel tank, because white/yellow 'WY' is what the white/blue 'WU' connects to (below, or see manual diagram) or connect Boyer white to 'switched' white (without the kill button) and if the kill button (WY) is disconnected as you say, then it's likely the WU won't have power unless it has been reconnected to white.

Image


Supercat wrote:Are you sure I'm not meant to be connecting the white-purple wire that the PO appears to have used to the white Boyer box wire?


Yes, I am sure :) and note the instructions say nothing about connecting anything to white/purple.
Unless the PO has drastically modified the wiring then the Boyer white should be connected directly to white/yellow or white.



Supercat wrote:And one more question - if I am able to get spark using the actual wiring instead of the bipass, am I better off running it like that if I wanted to make short trips around town (like less than 5 km at a time), or would I be better of just using the bipass setup while waiting for the new part to arrive?


If it works when connected correctly, then yes, use it that way as ultimately you will have to, but if in doubt, keep the bypass wiring with you so you can reconnect it in order to get home if something goes wrong.
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Re: Main fuse/Positive ground problems

Postby Supercat » Tue Sep 05, 2017 6:05 pm

Thanks L.A.B. and Paul!

Paul, I think I found the short. It seems to be a knackered zener diode. Well, I get an infinity reading on the ohms setting on the multimeter with it disconnected in any case. I'm very happy to be at this stage.

L.A.B., I've order a Podtronics unit from the website that you kindly sent the link for. It's one that allows for running the bike without a battery, which is great. I guess it sort of eliminates the need for 3 bike components (zener diode, capacitor and regulator), and potentially 4 (battery). That's amazing - I can't wait for it to arrive.

I have one more, possibly stupid, question about my wiring situation :). Would connecting the white/purple wires to the white Boyer wire, hooking up the battery, turning the key to on, and kicking to check for spark pose any risk to the ignition system, or anything else? I'd like to try this just because it looks like what the previous owner had done, but I'm not doing it if there is any risk.

I see what you mean about connecting the white main switch wire to the Boyer white wire, but I think I would need to cut the white switch wire and make a junction (if that's the right term for turning one wire into two) to get it to the Boyer. It seems to go on up to the front headlight at this point. I'd like to avoid cutting unless absolutely necessary :).

Thanks again!!

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Re: Main fuse/Positive ground problems

Postby texasSlick » Tue Sep 05, 2017 7:20 pm

Supercat wrote:Thanks L.A.B. and Paul!

Paul, I think I found the short. It seems to be a knackered zener diode. Well, I get an infinity reading on the ohms setting on the multimeter with it disconnected in any case.


Infinity reading on VOM implies an open circuit, not a short.

Since you are installing a Podtronics regulator, the Zener will be eliminated, but to determine if it is a possible short, test this way:

Disconnect wire(s) at the Zener tab.
Put red meter lead on Zener tab, black lead on frame ground. Meter should read some low value of Ohms .... 0.5 or so.

Reverse meter leads. Meter should now read infinity.

The Zener is shorted if the meter reads low Ohms with meter leads both ways.
The Zener is open circuited if meter reads infinity with meter leads both ways.

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Re: Main fuse/Positive ground problems

Postby Supercat » Tue Sep 05, 2017 8:20 pm

Thanks Slick I'll try that out.

When I was looking for the short I had the multimeter connected to the main leads that would normally connect to the battery. With the zener connected I was getting 00.0 ohms on the most sensitive setting. That means a short right? When I took the wires off the zener I got infinity.

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Re: Main fuse/Positive ground problems

Postby L.A.B. » Wed Sep 06, 2017 1:07 am

Supercat wrote:Would connecting the white/purple wires to the white Boyer wire, hooking up the battery, turning the key to on, and kicking to check for spark pose any risk to the ignition system, or anything else? I'd like to try this just because it looks like what the previous owner had done, but I'm not doing it if there is any risk.


No, there shouldn't be any risk, but make sure there are no other white/purples (WP) connected to the ignition coils (or anything else).

If you are determined to try connecting WP to the Boyer, then you must understand that with the ballast resistor disconnected/removed (which it must be for Boyer EI) the normal power feed to WP (from WU) will have been cut off, so for WP to feed power to the Boyer, WP must be (or must already be) connected to another part of the electrical system, the logical options being WY, WU, or W, however, as you've already said the kill button isn't connected, then there will be no electrical power reaching WY (if WY is actually there?) in which case there will also be no power to WU unless WU has been connected to W.


Supercat wrote:I see what you mean about connecting the white main switch wire to the Boyer white wire, but I think I would need to cut the white switch wire and make a junction (if that's the right term for turning one wire into two) to get it to the Boyer. It seems to go on up to the front headlight at this point. I'd like to avoid cutting unless absolutely necessary :).


Where is the Boyer box?
White (W) runs from the ignition switch to the main junction area under the fuel tank where it then branches off in different directions.
If the Boyer box is located in the usual place close to the coils (Boyer diagram, Figure 3) then the Boyer box white wire should be sufficiently long enough for it to connect directly to the W junction under the tank, and by doing so, bypasses all unnecessary (WP and/or WU) wiring.
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Re: Main fuse/Positive ground problems

Postby Supercat » Wed Sep 06, 2017 6:19 pm

Excellent, thanks L.A.B.! I haven't had a chance to try this yet. I worked late today and it was raining and almost dark by the time I got back so I kept her covered up. I will confirm that they're not connected to the coil before I do anything. I think the ballast resistor is still on there, and the last time I looked it seemed to still be wired. There may even be white/purple wires connected to that. I'll check that before proceeding. I take it that would be a reason to abort my plan :).

The Boyer box is in the usual place, but I don't remember seeing the white wire branch off in different directions under the tank. But I wasn't looking for that when I had everything exposed there, so I could have easily missed it. There are lots of wires, and lots of joined wires in that area. I guess one of the main reasons I'm so interested in the white/purple route is because there is a wire with the correct connector all ready to go there. If the white wire branches out and has a ready to go connector also, well... that would be perfect. The possibility of having to cut a wire, make a junction, find a connector and attach it makes me nervous :). I'll do it if I have to though. It sounds like I probably won't have to cut or make a junction though, so that makes me more comfortable.

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Re: Main fuse/Positive ground problems

Postby L.A.B. » Thu Sep 07, 2017 2:06 am

Supercat wrote:I think the ballast resistor is still on there, and the last time I looked it seemed to still be wired. There may even be white/purple wires connected to that. I'll check that before proceeding. I take it that would be a reason to abort my plan :).


If you use WP then you need to identify its power source.

If WP is connected to (so being fed from) the ballast resistor :shock: then you certainly need to disconnect it, also disconnect the 'other' ballast wire, normally the WU.

If WU has 12V power (Ign. on) then one option is to connect the WP and WU wires together, another would be to connect WU to the Boyer white as it says in the Boyer instructions instead of using WP.

Supercat wrote:I guess one of the main reasons I'm so interested in the white/purple route is because there is a wire with the correct connector all ready to go there. If the white wire branches out and has a ready to go connector also, well... that would be perfect. The possibility of having to cut a wire, make a junction, find a connector and attach it makes me nervous :). I'll do it if I have to though. It sounds like I probably won't have to cut or make a junction though, so that makes me more comfortable.


You may have to fit a bullet connector to connect Boyer white to W.
Removing unnecessary connections and lengths of wire generally helps to increase reliability especially where EI is concerned as they need a good electrical supply with no poor connections which is my reasoning for connecting the Boyer directly to W, but it's up to you.

In the interests of reliability, if it still has the original rubber junction block then I'd seriously suggest you replace it (or use separate double common etc. connectors, see BritishWiring link, below) also renew all the other 'bullet' connector sleeves on the bike as they are usually corroded and the internal metal tubes have often become brittle from age and can break up unseen inside the rubber sleeve.
concours wrote:

Image

Image


http://www.britishwiring.com/category-s/266.htm
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Re: Main fuse/Positive ground problems

Postby Supercat » Fri Sep 08, 2017 3:11 pm

Thanks a million L.A.B.!!!

I'm hoping to get to spend some proper time at the bike tomorrow, and I'm going to head out now shortly just to have a look at the wiring to see where the white from the main switch goes when it gets to the gas tank. I have a feeling the original rubber junction block is probably gone. There is a bit of a mess of bullet connectors along the left side of the top of the frame under the tank closer to the headlight. That situation definitely doesn't look stock, to my untrained eye anyway.

If I was able to get spark through the main harness instead of my bipass setup, would leaving the alternator disconnected eliminate my risk of damaging the ignition and the battery due to overcharging? I can wait till my part shows up before re-connecting the alternator.

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Re: Main fuse/Positive ground problems

Postby Supercat » Fri Sep 08, 2017 3:41 pm

K, I've just had a look, and the original rubber junction appears to be gone. It may be buried in the mess of bullet connectors I mentioned, but if it's there it's not obvious. There are also still white/blue and white/purple wires connected to the old ballast resistor.

I did notice that there is a double set of white wires that are not connected to anything that seem to come from the main switch and that end with a connector that dangles just in the rear end of the battery box. Are those good candidates for connecting to the Boyer white wire? Should I connect the battery and use the multi-meter to look for power on those with the switch turned to on? I could run a wire from those up to the Boyer box wire fairly easily and that wouldn't require any cutting. I could even use my negative bi-pass wire to make that connection with relative ease. It's plenty long enough.

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