Accuracy of Wiring Diagram in the Shop Manual

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rwalker28

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I hope this has not been asked and answered, if so point me in the right direction (I tried search...) I have two questions: 1) My '74 850 came non running. One reason is the wiring is all botched up by PO. Should two bullet connections be shoved into the non- wiring loom end of one of the 5 way lucas connector holes (or the other end for that matter?) I think not, but one learns new things every day. Looks like the PO's theory of electrical systems is to connect all the same colors together, and improvise if there is not enough things to plug into. Or randomly leave things not connected. 2) I have a Norton workshop manual for 750/850 from 1970 (no other way to date it.) How accurate is the wiring diagram in that? Are there known errors? I ask because I think they call the left hand cluster the right hand cluster and vice versa. I have to do this from scratch, and I am no electrical guy - I am a chemical engineer. (I keep telling myself...just remember wires are like pipes and current is like water flow, resistors are like valves...arrrrgggggg.)
 
The manual has it right but looking at the loom real time is confusing as there are many dead end ground loops and power leads for police equipment. I gave up on my first one and took it apart, ugh, to remove half a shoe box of trash and piece together the loom with just the needed colors and amounts of wires. The bar swtiches can be put on either side to confuse ya so do them on side you like them to be. The head lights and indicator lamps was the wierdest for me to get right.
 
I made a copy of the wiring diagram and used colored pencils to trace out each circuit. Try to use colors close to the colors of the wiring . That way, each circuit stands out on it's own.
 
rwalker28 said:
2) I have a Norton workshop manual for 750/850 from 1970 (no other way to date it.) How accurate is the wiring diagram in that? Are there known errors? I ask because I think they call the left hand cluster the right hand cluster and vice versa.
Click to expand...

The fact that you may have found the switch clusters fitted the reverse way to how they are shown on the wiring diagram was often a matter of rider or dealer preference, and the factory eventually swapped them over on later models.
 
rwalker28 said:
I hope this has not been asked and answered, if so point me in the right direction (I tried search...) I have two questions: 1) My '74 850 came non running. One reason is the wiring is all botched up by PO. Should two bullet connections be shoved into the non- wiring loom end of one of the 5 way lucas connector holes (or the other end for that matter?) I think not, but one learns new things every day. Looks like the PO's theory of electrical systems is to connect all the same colors together, and improvise if there is not enough things to plug into. Or randomly leave things not connected. 2) I have a Norton workshop manual for 750/850 from 1970 (no other way to date it.) How accurate is the wiring diagram in that? Are there known errors? I ask because I think they call the left hand cluster the right hand cluster and vice versa. I have to do this from scratch, and I am no electrical guy - I am a chemical engineer. (I keep telling myself...just remember wires are like pipes and current is like water flow, resistors are like valves...arrrrgggggg.)
Click to expand...

I found that looking at the manuals wiring diagram is like some mechanical drawings in the sense that you are looking up at the system from underneath. So at first glance of the drawing it would almost appear as though to be backwards, creating the effect of the R/H cluster switch looking like it is on the what most would consider as the left hand side of the drawing.
This is fresh in my head as I am just about complete my wiring harness on my 72 750 as of last night.

http://i1243.photobucket.com/albums/gg5 ... 957fbf.jpg
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http://i1243.photobucket.com/albums/gg5 ... a2c4b9.jpg
 
Hi folks, thank you for the replies. This list is great. I intend to make a new wiring loom now, good to know the interpol stuff is in there, and not needed. I mistakenly thought the right hand control cluster was an integral part of the hydraulic brake master cylinder assembley, so it had to be in the right side. However, I see now. PO must have swapped it. I had a 72 750 back in 1977, and as I think about it, the controls could have been switched around, but that is a lot of beers ago. And I do have one of those laminated wiring diagrams from that guy for both the Norton and the Austin Healey, they are really good to have.
 
After removing the police clutter its a lot easier to deal with and can even switch bar controls and its buttons wireing to work with the desired hand. There is an unused intermittent button on the factory RH switch cluster you can use for what ever or leave useless. Note the signals if you have them earths back through the chromed plastic so some of us run a extra return wire or time to time just smack the living daylights out the single stem to get it blinks for a time till next blank state to smack back to function again and again. About worse thing to re-wire is the dang rear brake light swtich, simple as it appears. A relay added for the head light is good idea to get bright beam and less heat in the handle bar switches.
 
Thanks again.I will look into old post to decide what to do, I am leaning toward neg, ground, electronic ignition, upgrade the whole thing, so when I get there I will have a lot of questions. Still tearing it down, not a lot of spare time, but it'll get done sooner than later...
 
Staticmoves, that is the cleanest rewiring job I have ever seen. I just went out and looked at mine, with the tank off. I cried.
 
staticmoves, can you add more pics?
I am going thru the same hell and be good to see how a well done work looks like...
 
Orsonoce said:
staticmoves, can you add more pics?
I am going thru the same hell and be good to see how a well done work looks like...
Click to expand...

AND DIABLOUPH

Thank You for the complements on my wiring guys.
By no means am I a pro, and this is my first resto ever. If you think some more pics will help you out, then I will shoot some this week and post for you.
( by the time I take the photos, pull the film, get the film to the developer, he developes the film, the film drys, the delvleloper calls me, I pick up the photos, then scan the photo's, photocucket the scans, and post............. you know what, I'll just use the phone camera 8) )
 
staticmoves did you buy a new wiring loom, or restore an old one. If you restored the old one how did you clean it?
 
marknorton said:
staticmoves did you buy a new wiring loom, or restore an old one. If you restored the old one how did you clean it?
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I bought a new wiring loom, after 40 years sheathing breaks down, and i am looking to enjoy the motorcycle as much as I can.
P.S...... I am new to Nortons and I am sure it will throw me enough curve balls without having to worry about 40 year old wiring 8)
I guess I may have over answered your question, but hey! what are FORUMS for!
 
Can you tell me where you purchased the new one from as well as the cost? Are wiring colors identical to the original? Mine is also a mess, and I ma interested to compare what your costs are to ours here in the UK.
 
marknorton said:
Can you tell me where you purchased the new one from as well as the cost? Are wiring colors identical to the original? Mine is also a mess, and I ma interested to compare what your costs are to ours here in the UK.[/quotI)

My commando is 72 750 (decombated from preveoius owner ) I paid $149.95 for main harness and $61.20 for head light harness, currency was CAD and all original color scheem. I purchased from walridge motors in London Ontario, funny enough most of there parts come from your back yard, though not to sure about the harness.
I found it was built well and no slop left in it once installed, everthing fit good.
P.S. while I found this was a great harness, if your up to the task I would believe most of the experienced members on here would most likley incourage you to build your own harness out of higher quality wire than most pre made looms.
Hope this helps 8)

http://i1243.photobucket.com/albums/gg5 ... 259208.jpg
Now did you notice my makeshift stool. ( hey either I bought a respectable stool, or doubled my compost bin as a stool and bought a new CNW crankcase breather. So I did what any self respecting motorcycle enthusiast would do ) 8)
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Build yer own.
Make all the relay upgrades (horn, headlight, brake light) part of your design so not to cobble up a "new" harness.
Look at the problem from the other perspective. Making your own harness will make you infinitely familiar with it's design for future troubleshooting which you probably won't need to do.
You also get to decide what the switch clusters do. Who cares what the factory wanted unless your going concourse restoration.
I had the dummy N.O. pushbutton as a kill switch and flipped the high/low beam control to the other side.
XBSKT2 will have a relay wired through an oil pressure switch on all circuits that draw power except the ignition so that my ignition gets max voltage at startup until oil pressure closes the pressure switch which closes a relay and turns the lights on.
Things like that are the way I make the bike my own. Your results may vary.
Don't worry about the color of the wire. It makes no difference to the electrons. Make a schematic of your own that you understand on a large enough format that you can see it all easily.
Positive ground or negative ground both have their followers. Make your choice but know that once an electron leaves the battery it just wants a return path.
As a final thought I would wager that you can build your own including shrink stake-ons. a quality buss bar for grouping "ground" terminations, sheathing, wire ties and a fuse block for much less than a new loom from a vendor.

Your building or rebuilding most of the bike. You can definitely handle building a wiring harness.

HTH,

Jeff
 
I would make my own loom, but don't know if "all white wires" is a good idea.
 
Orsonoce said:
staticmoves, can you add more pics?
I am going thru the same hell and be good to see how a well done work looks like...
Click to expand...

Here are some pics as you requested of my wiring setup. Again I am no pro and there may be some good feed back on how I could improve my setup.
Cheers!

http://i1243.photobucket.com/albums/gg5 ... 116a07.jpg
A pic of the rectifier and flasher unit clip ( flasher unit in mail and rectifier unplugged as I have a Boyer powerbox in system )
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Zenner diode and positive earth ground installed and connected
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Wire run to tail light and rear signals
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Harness around oil tank, wire on left going to rectifier and flasher unit and rear brake switch, wire on right going to zenner and earth ground.
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Wires neatly tucked up in tail piece.
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Purple black is horn, and wires running down beside oil tank are charging socket and alternator
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Charging jack and alternator wires, and you can see recently installed oil filter in lower cradle.
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Another side shot of under tank harness, Boyer ignition box, and the head steady that will be replaced next winter :D
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Taking a break in echo valley Saskatchewan , ( had to throw that pic in, I love it ) 8)
 
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