Trying to revive a 1973 Roadster

Welcome to the forum.

I especially love the cylinder painting / masking photo. That is a hoot and a half.

When I cleaned the wiring harness I did it in place and didn't disconnect anything. When I was 16 in 1973 I had a new H2. The town I live in has about 3500 people in it and the Norton dealer in town sold 12 new Nortons in our town in 1973, they were everywhere. I have never ridden one and back then we thought they were pretty lame compared to our Kawi's but now I think they are a very nice bike. I am still probing around but can't seem to find the missing juice. I live in the northern part of SD so if anyone is close I could use a little guidance. :? I'm heading out to the garage to do the coil test Matt suggested.

First off as Dave said get a wiring diagram and STUDY IT. These bikes get a bad rap for their electrics and some of it is earned but mostly it is lack of maintenance and understanding of the owner. But in reality it is simple point to point wiring. First off check to battery. Even if it is new. 12+ volts is a must. Then attached the red lead from your volt meter to the positive terminal. Then using the wiring diagram start tracing the voltage. If there is no power to the switch then the wire could be broken or an interim connection is broken. Check the continuity of the wire. Since you are not popping fuses does not sound like a short. Work slowly and have patience keep reminding yourself this is a learning experience that will pay off late at night on a dark lonely road. Anybody who has the patience to mask off the whole bike to paint the cylinder in place can do this.

Start with a good wiring diagram (must have). I'm far from expert with wiring & I've been able to do deal with just about any upgrades and cleaning up of the harness so you should too.. Be aware that time may have discolored things, while tracing wires I couldn't understand why I didn't see what the diagram said until I realized that some solid or striped wires that were blue had turned green from time,, if your not shure check a wire under the wrapping to find the true color.. Oh and welcome, love that color gold!!

I have been looking at wiring diagrams for days and I've never seen a bike that has so many variations. I still don't know if I am even looking at the right one for this bike. I have also been wondering about the silver cylinders, was there a particular year or model that had them? The black or silver clock housings is a mystery to me too. I'm using a lithium ion battery and I've checked the voltage probably 10 times during this to make sure it isn't getting weak and so far it has always showed 13.2 volts.

Guts,
You say there is power at the fuse. The next place to check is the ignition switch. One of the wire at the switch must show power with the switch in the off position. Connect one wire from your VOM to the positive side of your battery and probe the blades on your switch. If none of them test hot the problem is from the fuse to switch. If you get power @ the switch remove the VOM lead from the battery (positive side) and connect it to various ground points on the frame and engine If you still show voltage the problem is in the switch or wiring after the switch. If you don't get a reading then the problem is no ground from battery to frame/engine.
Reading a wiring diagram will not help you until you get power to the switch and a good ground back to the battery. I think this is where your problem is. I believe your switch is located near the battery so it should be a simple trace. From this point on you will need a wiring diagram to simplify matters. Hope this helps.
Pete

GUTS said:

I have been looking at wiring diagrams for days and I've never seen a bike that has so many variations. I still don't know if I am even looking at the right one for this bike.

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It's the diagram shown in the factory manual shown for 1972 and 1973, section J Fig. J11, however, you may find some additional wires in the harness that are not on the diagram, these can usually be ignored.
http://www.classicbike.biz/Norton/Repai ... mmando.pdf

GUTS said:

I have also been wondering about the silver cylinders, was there a particular year or model that had them?

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Silver would generally be correct for 1973 750 and 850 models.

GUTS said:

The black or silver clock housings is a mystery to me too.

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The deeper black items would be correct for 1973.

So was black before and after or could you get both. A friend of mine bought a new orange '73 and he recollected it had a black cylinder and silver gauges.

I did a continuity test on the brown and blue wire that goes from the negative battery post, through the fuse and to the switch and it showed continuity from the battery to the switch. I just tested it again and had none so I took the fuse holder apart(and found the connection holding by one wire) and used a test clip wire to replace the small length of wire on the battery side to eliminate the fuse holder.
Here is the meter reading with the probes hooked to the negative battery post and the spade where the brown and green wire attach to the switch.


Here it is with the lead on the positive battery post.


Here is the bad connection.



Even bypassing the fuse holder and getting power tot he switch, it still energizes nothing when I turn the key to the various positions.

I also hooked the battery direct to the coil and had no spark at the points.

GUTS said:

I have been looking at wiring diagrams for days and I've never seen a bike that has so many variations. I still don't know if I am even looking at the right one for this bike. I have also been wondering about the silver cylinders, was there a particular year or model that had them? The black or silver clock housings is a mystery to me too. I'm using a lithium ion battery and I've checked the voltage probably 10 times during this to make sure it isn't getting weak and so far it has always showed 13.2 volts.

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Yeeeaaahhhh..... Somehow it was decided ALL Commandos would use the wiring harness for the Police variant. So, much unused wire, connectors. Made sense to someone, at some time. I guess. :roll:

now check:
1) continuity from frame and engine to to positive battery.
2) voltage from hot switch connection to bike frame and engine

GUTS said:

So was black before and after or could you get both. A friend of mine bought a new orange '73 and he recollected it had a black cylinder and silver gauges.

I did a continuity test on the brown and blue wire that goes from the negative battery post, through the fuse and to the switch and it showed continuity from the battery to the switch. I just tested it again and had none so I took the fuse holder apart(and found the connection holding by one wire) and used a test clip wire to replace the small length of wire on the battery side to eliminate the fuse holder.
Here is the meter reading with the probes hooked to the negative battery post and the spade where the brown and green wire attach to the switch.

Here it is with the lead on the positive battery post.

Here is the bad connection.

Even bypassing the fuse holder and getting power tot he switch, it still energizes nothing when I turn the key to the various positions.

I also hooked the battery direct to the coil and had no spark at the points.

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No output from switch? Jump it out to test.

GUTS said:

So was black before and after or could you get both.

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It's slightly complicated, as a general rule they were normally silver before 1972, for 1972, Combat barrels were black, and silver for standard models. Silver barrels were standard for 1973, and '74-on they were normally black once again.

GUTS said:

A friend of mine bought a new orange '73 and he recollected it had a black cylinder and silver gauges.

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It was probably a late '72 model then. Instrument pods were usually black 1973-on.

If your bike has that five slot big connector that concours shows, I would have a look there. Better to replace it with 5 two place connectors. Also, most bikes have had their ignition key left on inadvertantly at one point in their life. If the points happen to be closed at the time, current flows continually through the ignition circuit. This can melt the white feed wire which is buried in the fat group of wires under the tank. Been there and seen that. Keep at it.

There is a free terminal on the ignition switch that gets power when in the on position. I use that terminal to feed my ignition system. This bypasses the handlebar kill button which can be problematic. I also keep a jumper lead off the neg battery terminal with a male spade taped up on the end. If you get a blown fuse while on the road and cannot find the fault, you simply pull the ignition feed wire off the switch and plug in the spare wire you have installed on your battery. This , hot wires, the ignition system and you are on your way again. You will have no other electrical functions but the bike will carry you home. To me it is a no brainer to set it up like this. My experience was with a closed circuit zener diode which instantly popped the fuse. In closed circuit, you have direct battery load to ground versus the zener doing its job of monitoring the voltage and dumping to ground as needed. If you ever notice the zener heat sink getting hot/warm as you charge your battery, this the zener doing its job of regulating the battery voltage. I do not think it is a good idea to leave a charger on a Norton for an extended period. Overworks the zener.

Continuity from frame-engine to positive battery, 13.15volts.
Voltage from switch hot lead to frame engine, 0 volts.

You have to realize that when reading voltages with a modern VOM, the input resistance of the meter is so high, it will mask any voltage drop in the circuit you're measuring. You need to measure voltages at the end point with the load (ignition or headlamp) connected and on, it may be that a connector or a switch may have large resistance (rust or bad connection) and absorbs all the voltage the battery is producing. You can only tell when the load (ignition or headlamp) is connected and on and measured at the load (ignition or headlamp). If there's no current going through the circuit (not on), it will always read full battery voltage with a good VOM. I hope this makes sense. If you don't understand, it can be very confusing and lead you down a rabbit hole real quick.

That's why I say hot wire it, bypassing the current harness and connectors and you can go from there, and I mean the + 'earth' too. Connect 2 leads right from the battery to the ignition circuit, observing correct polarity and see if you get spark. It would surprise me if you don't, but not impossible, there could be something wrong in the ignition circuit but until you get rid of the harness issues (if there are any) it'll be difficult, like shooting in the dark.

I can't see exactly what's going on in the second photo but the meter probes seem to be reversed? Or is it set to Ohms?
What exactly is the black wire with the crocodile clip connected to, as the first photo doesn't show it connected to the battery post?

GUTS said:

Here it is with the lead on the positive battery post.

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You know what Les I think he has his battery reversed. On positive ground fuse should be on negative terminal.

O.My. Gawd. Reversed battery leads can also toast the rectifier in an instant. Good eyeballs. Whole new can o' worms. :|

It's connected to the brown/blue wire that would come from the negative battery terminal, I replaced the fuse holder with the alligator clipped wire. I also connected the battery direct to one of the coils and checked the points for spark and had none.