Coil, ballast, condenser pack wiring 1971 commando Roadster (2018)

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Wilson

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I'm attempting to sort out my 1971 Norton Commando. Trying to put it back into service. Unfortunately all the wiring around the coils ballest resistor and asimulator has been unplugged. I'm trying to find some clear pictures if anyone has such a thing they could forward me that I could see where the wires go. I have all the different wiring diagrams but everything around the coils points and condenser's is very vague as to equal the amount of wires I have left over to put things in. Any help would be appreciated. Thank you
 
Wilson said:
I'm attempting to sort out my 1971 Norton Commando. Trying to put it back into service. Unfortunately all the wiring around the coils ballest resistor and asimulator has been unplugged.
Click to expand...

Has electronic ignition been fitted? If so, then you may not want to connect the ballast resistor or condensers at all.



Wilson said:
I have all the different wiring diagrams but everything around the coils points and condenser's is very vague as to equal the amount of wires I have left over to put things in.
Click to expand...

If you concentrate on the 1971 diagram and connect the wires according to the colour codes (and don't attempt to overthink things) then the ignition wiring is reasonably straightforward.

WY (white/yellow) from the handlebar kill switch connects to WU (white/blue) at the connection under the fuel tank.
WU to ballast, then (probably) white/purple (unmarked on diag.) from the ballast to each coil (-) terminal.
Black/white from RH coil (+) to points and one condenser.
Black/yellow from LH coil (+) to points and one condenser.

Edit: Coil polarity corrected.

The assimilator wire connections are:
WL - White/brown (WN)
AL - Green/yellow (GY)
E - Red.


Note that you probably will have some 'extra' wires left over which are not used so can be ignored.
 
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L.A.B. said:
Has electronic ignition been fitted? If so, then you may not want to connect the ballast resistor or condensers at all.





If you concentrate on the 1971 diagram and connect the wires according to the colour codes (and don't attempt to overthink things) then the ignition wiring is reasonably straightforward.

WY (white/yellow) from the handlebar kill switch connects to WU (white/blue) at the connection under the fuel tank.
WU to ballast, then (probably) white/purple (unmarked on diag.) from the ballast to each coil (-) terminal.
Black/white from RH coil (+) to points and one condenser.
Black/yellow from LH coil (+) to points and one condenser.

Edit: Coil polarity corrected.

The assimilator wire connections are:
WL - White/brown (WN)
AL - Green/yellow (GY)
E - Red.


Note that you probably will have some 'extra' wires left over which are not used so can be ignored.
Click to expand...
L.A.B
All the diagrams show the points going to the positive side of the coil not the negative? The thing is whenever I'm trying I'm still not getting the plugs to fire. The coils or hot or at least they have power please confirm again that the points actually attached to the negative side of the coil.
 
I see the correction. No matter what position I have the key switch the coil always shows power. But I'm still not getting any spark at the plugs.
No matter what position I have the key switch the coil always shows power. But I'm still not getting any spark at the plugs.
 
Wilson said:
No matter what position I have the key switch the coil always shows power.
Click to expand...

Something wrong there, as power should only be reaching the coils with the key at either "Ignition only" or "Ignition and lights".

Coil, ballast, condenser pack wiring 1971 commando Roadster (2018)


Wilson said:
But I'm still not getting any spark at the plugs.
Click to expand...

Do you get voltage across the (open) points?

Check the points terminals are fitted correctly with each ring terminal under the nylon insulator as shown below, not directly under the nut.

Coil, ballast, condenser pack wiring 1971 commando Roadster (2018)


Check there is a good ground/return connection between the engine and battery (+).
 
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L.A.B. said:
Something wrong there, as power should only be reaching the coils with the key at either "Ignition only" or "Ignition and lights".

Coil, ballast, condenser pack wiring 1971 commando Roadster (2018)



Do you get voltage across the (open) points?

Check the points terminals are fitted correctly with each ring terminal under the nylon insulator as shown below, not directly under the nut.

Coil, ballast, condenser pack wiring 1971 commando Roadster (2018)

Check there is a good ground/return connection between the engine and battery (+).
Click to expand...
Yes, my test light lights up when touching either side of the open point, this is it the test light attached to the negative side of the battery. My ignition switch is very primitive. Only two positions from center, one left back to center and one right. I did have the bike running a couple years ago for a couple of min with all the same components. Also if it matters there is a three white wire coupling which I believe connects from the left side combi switch where I have the "kill" button wired. I noticed that connection gets really hot, so I have unplugged it. That white wire is always " has voltage. I'm about ready to strip the hole thing ,get a new ignition switch and start from scratch. Also which color wire brings voltage to the ignition switch or does it ground to the frame?
 
Wilson said:
Yes, my test light lights up when touching either side of the open point, this is it the test light attached to the negative side of the battery.
Click to expand...

That doesn't sound right. Did you check volts from each coil-side point to ground with the points open?


Wilson said:
My ignition switch is very primitive. Only two positions from center, one left back to center and one right. I did have the bike running a couple years ago for a couple of min with all the same components. Also if it matters there is a three white wire coupling which I believe connects from the left side combi switch where I have the "kill" button wired. I noticed that connection gets really hot, so I have unplugged it.
Click to expand...

White is "switched" power.
If the white wire to the cluster containing the kill button is disconnected then it will cut the power supply to the ignition.


Wilson said:
That white wire is always " has voltage.
Click to expand...

It should have voltage with the ignition switch ON but not otherwise. The fact that the wiring is getting hot suggests something may not be connected correctly.


Wilson said:
I'm about ready to strip the hole thing ,get a new ignition switch and start from scratch. Also which color wire brings voltage to the ignition switch or does it ground to the frame?
Click to expand...

Try not to overthink, use the wiring diagram.

These bikes are positive ground as standard, negative is the 'feed', which, if you study the wiring diagram is the brown/blue (NU) wire from battery (-) to the ignition master switch.
 
I think your "start from scratch" idea is a good one. As noted, there will be more wires in the OEM harness than you will have places to connect them. My approach would be to disconnect everything and then, with the service manual wiring diagram in hand, reconnect each item per the diagram while also cleaning each connection with DeOxit or something like that. I wouldn't even check anything else first, just pull every bullet/spade connector and start over.

The ignition switch might also have connection issues internally but that can be checked with a multimeter. As noted, there should be no power at the coils with the ignition switch off. But if the incorrect wires are connected at the switch or at the coils, OR the switch is internally shorted, power could be applied at all times. The fact that the white wire coupling is heating up also points to something being incorrectly connected.

Though not related to the problem, ensuring you have good grounds to the engine/frame is also a good thing. Adding a new ground wire to the engine and frame from the pos batt terminal will ensure that ground continuity is never an issue. The wiring harness/oem connectors for that purpose tend to be a bit questionable over time.
 
Hi Wilson, I see your inquiry is 18 months old but we must have the similar situation? Perhaps you can help?
My buddy has a 71 Commando,he had an individual make up a new gas tank. For some unexplained reason they disconnected all the wiring front and rear of the bike (don't go there!).
I have succeeded in getting all the lights and horn working and connected the points and coils as per diagram, but even if "I don't attempt to over think things", there are two things I'm having a problem with;

1). The wiring diagrams show a two spaded ballast resistor which I have located but directly behind that is a resin filled black box?? with three male spades protruding,one is an obvious ground, the the other two ?? What is this black box, as I don't seem to be able to find it on any any wiring diagrams I have....
2). Around the coil area I have four female spaded connectors; BL, BW, BW & BY, all single wires except one WB which has two wires connected to the spade.
Question; Where on the two modules do these wires connect?
 
laurieretired said:
1). The wiring diagrams show a two spaded ballast resistor which I have located but directly behind that is a resin filled black box?? with three male spades protruding,one is an obvious ground, the the other two ?? What is this black box, as I don't seem to be able to find it on any any wiring diagrams I have....
Click to expand...

That's the 2CP ignition condenser pack. The condensers are drawn parallel to the points on the diagram and not as the condenser pack.
Coil, ballast, condenser pack wiring 1971 commando Roadster (2018)


laurieretired said:
2). Around the coil area I have four female spaded connectors; BL, BW, BW & BY, all single wires except one WB which has two wires connected to the spade.
Question; Where on the two modules do these wires connect?
Click to expand...

"BL"?
"WB"?

One BW connects to a condenser terminal and BY to the other.

Are you sure it is a second "BW"? Edit: Or did you mean WB (white/black or white/blue)?
Power to the ballast is white/blue WU.
Ballast to both coils (-) is white/purple (not marked on diagram).

There should also be a red to the 2CP 'ground' terminal.
 
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