Norton 650ss Wiring problems

John W

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Sep 17, 2022
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The Norton Wiring being 40 years old with many repairs & blowing the only fuse. Decided to replace with the Lucas wiring loom pn 54935175
this meant a replacement main light switch assy pn 34289.
On fitting these to the Norton 650SS & connecting the 12V battery all new, the Ammeter shows 1 to 2 amps current no wires appear to be getting warm, The light switch does nothing, checking the new switch no voltages appear on any of the contacts, which makes me think is the switch compatable to the switch assy, as sold by Norvil. The wiring diagram supplied by Lucas is very basic showing 3 read wires at the Battery end of the loom. 2 red wires having loops on are connected to earth as the bike has a @Positive earth. The 3rd red wire is connected to the Rectifier +ve input.
No lights work, the Zener diode measures 750K ohm, but would not have an effect on lights in a stationary condition. Has any one else had these problems? It should be simple but not is with old motor electronics
John
 
Sounds like a bit of fun, but pretty hard to diagnose remotely.
For me thing one is to understand the original wiring diagram, including how each item is earthed, and then check whether each item you are connecting to the wiring is correct for that diagram. Should, and do, switches make or break the circuit for instance? If power is getting to something, is it properly earthed to complete the circuit. A multimeter and some patience will come in handy.
 
ntst8 said:
Sounds like a bit of fun, but pretty hard to diagnose remotely.
For me thing one is to understand the original wiring diagram, including how each item is earthed, and then check whether each item you are connecting to the wiring is correct for that diagram. Should, and do, switches make or break the circuit for instance? If power is getting to something, is it properly earthed to complete the circuit. A multimeter and some patience will come in handy.
Click to expand...
[,ve got lots of patience worked on laptops & in the computer industry. Got the Diagram of the 650SS it all looks simple
but auto electronics is another field altogether, visiting Norvil next week the guy who,s got all the part numbers in his head
should be back from holiday. I was advising them last visit on what was needed. Think its Les or Len He told me the parts I took in one was of a Matchless Scrambler the other of a BSA Goldstar all bikes my brother owned.
 
Do you have a 650 SS wiring diagram? You are lost in the dark without one.

Slick
 
marinatlas said:
granttiller.com

Grant Tiller | Custom Norton Dominator 650ss Wiring Diagram (Greg Marsh Enterprises)

Greg Marsh from the Access Norton forum reached out to ask for some assistance with a wiring diagram. Greg is doing some work on a Norton Dominator 650ss - a bike I adore. The wiring is in a bit of a mess, so Greg is in the process of sorting it out. It has a
granttiller.com granttiller.com
Click to expand...
The 650SS wiring is very simple if an electronic ignition and sold-state rectifier/regulator are used as in my custom diagram. If you still have points, rectifier and Zener, its best to look at an original diagram. Have a look here: https://www.gregmarsh.com/MC/Images/68-Workshop.pdf
 
You didn't tell if your 650SS has magneto or points ignition. Different wiring on them. Also different wiring on later ones with two wire alternator and zener diode.
Something is drawing current ( how much is hard to tell as the ammeter is not very exact ). So disconnect one at a time those things that can draw current.
Personally I've never fitted a new wiring loom. Prefer separate wires except to headlamp. First rewiring of a Norton in 1966.
 
Mike40M said:
You didn't tell if your 650SS has magneto or points ignition. Different wiring on them. Also different wiring on later ones with two wire alternator and zener diode.
Something is drawing current ( how much is hard to tell as the ammeter is not very exact ). So disconnect one at a time those things that can draw current.
Personally I've never fitted a new wiring loom. Prefer separate wires except to headlamp. First rewiring of a Norton in 1966.
Click to expand...
It has points & Magneto & Zener diode Try and get an answer on Thursday if its a compatability problem
 
My fault. I should have written magneto or coil ignition. All magneto ignitions I've seen has points.
 
Magnetos have points but magneto ignitions do not have coils.

Regarding tracking down source of current draw: Divide and Conquer....... Disconnect one Circuit branch at a time, looking to see if current draw stops.

Slick
 
John W said:
The Norton Wiring being 40 years old with many repairs & blowing the only fuse. Decided to replace with the Lucas wiring loom pn 54935175
this meant a replacement main light switch assy pn 34289.
On fitting these to the Norton 650SS & connecting the 12V battery all new, the Ammeter shows 1 to 2 amps current no wires appear to be getting warm, The light switch does nothing, checking the new switch no voltages appear on any of the contacts, which makes me think is the switch compatable to the switch assy, as sold by Norvil. The wiring diagram supplied by Lucas is very basic showing 3 read wires at the Battery end of the loom. 2 red wires having loops on are connected to earth as the bike has a @Positive earth. The 3rd red wire is connected to the Rectifier +ve input.
No lights work, the Zener diode measures 750K ohm, but would not have an effect on lights in a stationary condition. Has any one else had these problems? It should be simple but not is with old motor electronics
John
Click to expand...
hello well the 1960 Norton 650 Manxman and later 650ss 1962 on1963 had the lighting switch sa47 after this the lighting switch changed to sa88 lighting switch to the end of 1969/70 Norton mercury so there for two different wiring harness and wiring patients
 
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