I need some help please.

Hello Guys,

I have a simple but disheartening problem. I have had my 1974 Commando in heated storage for three years, and due to dire financial circumstances I have to sell it. I went through everything to get it running again re full service, but when I put the fully charged battery in it it has no power to any lights. I vaguely remembered that when I took the battery out three years ago, that a black wire with a copper eyelet came loose from the harness. Presumably this wire went from the harness to the battery. I desperately need guidance from someone to get this bike running so I can sell it. I am in genuine need of someones help. I am able to follow direction, but cannot search through endless threads to try and diagnose this my self. I am aking for some genuine help. The bike is not a beater.......it is in wonderful condtion, and I am heartbroken for having to sell it.

I am located in St.Catharines Ontario Canada.....so if anyone local can assist it would mean the world to me and my family. I would be willing to pay someone local to diagnose. I do not want to sell a non running bike for fear of loosing so much money for such a simple problem. The gentleman who built the bike has retired and closed shop.

Thank you sincerely ,

David

islanddave said:

I vaguely remembered that when I took the battery out three years ago, that a black wire with a copper eyelet came loose from the harness. Presumably this wire went from the harness to the battery. I desperately need guidance from someone to get this bike running so I can sell it.

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There would normally be a brown/blue wire (with an in-line fuse) and ring terminal that connects to battery negative and red(s) with a ring terminal that connects to battery positive.


If there's a "loose black wire" then it's probably the battery negative wire (because there's no black wiring in the standard electrical system), therefore, should connect to the harness brown/blue.

Do you have a volt-ohm-meter (VOM)? If you don't have a VOM, you can buy one for twenty or so dollars at Canadian Tire or some auto parts store. If yes, check the resistance between the fused wire (color/s might vary depending on what the previous owner did) and chassis ground with the ignition switch on. The resistance should be something considerably less than infinity. With the headlight switch on you should get less than 10 ohms. You are looking for a corroded connector or blown fuse between battery, hot (black) and the rest of the system. The Red wire(s) should show a dead short to ground. With the main switch off you will measure the resistance of the zener diode regulator. With the test-leads one way, say black to black, you may forward bias the zener and get some ohm reading other than infinity while with the leads reversed you should get infinity or close to it. With the switch on you should not get infinity either way; If you do there is a blown fuse, broken or corroded wire/connection in the hot circuit.

islanddave said:

Hello Guys,

I have a simple but disheartening problem. I have had my 1974 Commando in heated storage for three years, and due to dire financial circumstances I have to sell it. I went through everything to get it running again re full service, but when I put the fully charged battery in it it has no power to any lights. I vaguely remembered that when I took the battery out three years ago, that a black wire with a copper eyelet came loose from the harness. Presumably this wire went from the harness to the battery. I desperately need guidance from someone to get this bike running so I can sell it. I am in genuine need of someones help. I am able to follow direction, but cannot search through endless threads to try and diagnose this my self. I am aking for some genuine help. The bike is not a beater.......it is in wonderful condtion, and I am heartbroken for having to sell it.

I am located in St.Catharines Ontario Canada.....so if anyone local can assist it would mean the world to me and my family. I would be willing to pay someone local to diagnose. I do not want to sell a non running bike for fear of loosing so much money for such a simple problem. The gentleman who built the bike has retired and closed shop.

Thank you sincerely ,

David

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Hi Dave. You could try contacting the local vintage bike club
I’m sure somebody would be happy to help. Best of luck.

I'm in Toronto . You are in St C. , a good 3 hrs 401 driving time X 2 .
Keep posting and we can help you through it. It's positive ground.
Dereck Wilson just north of you in London is a great option .

Hi David
Hope you get your bike sorted and get a good price for it
I've been there twice in my life so far
I had to let go a mint mk2a the first time
And 3 bikes the second time it happened

Hi David , I’m feeling bad you parting with your Norton for $ reasons , these are hard times for sure …. Do you have inline fuse on either wire from battery (check visually) also check any others you can find , did you reconnect this black wire with copper ring connector ? Also, maybe trace this black wire from battery along through the harness and check any connections along the length of it …. With the Norton mostly I just just used a test light to trace troubles …. under $2 at CT …. Very best of luck !

Spray all the connectors and handlebar fittings saturate with C R C .

Likely dry & oxidised . if its contact breaker points set up - Id wipe them clean too .

CAREFULLY throwing a jum start - connection to a whole Car or Truck battery , should get the juice flowing .

What is impedance? Impedance, denoted Z, is an expression of the opposition that an electronic component, circuit, or system offers to alternating and/or direct electric current. Impedance is a vector (two-dimensional)quantity consisting of two independent scalar (one-dimensional) phenomena: resistance and reactance.

Just as an asside . A FLAT BATTERY often needs a few hours on a charger just to start to wake up , and a L O N G overnight charging , then a bit of cycling , to get all the enzimes in order , as theyre dormant .

Matt Spencer said:

Spray all the connectors and handlebar fittings saturate with C R C .

Likely dry & oxidised . if its contact breaker points set up - Id wipe them clean too .

CAREFULLY throwing a jum start - connection to a whole Car or Truck battery , should get the juice flowing .

What is impedance? Impedance, denoted Z, is an expression of the opposition that an electronic component, circuit, or system offers to alternating and/or direct electric current. Impedance is a vector (two-dimensional)quantity consisting of two independent scalar (one-dimensional) phenomena: resistance and reactance.

Just as an asside . A FLAT BATTERY often needs a few hours on a charger just to start to wake up , and a L O N G overnight charging , then a bit of cycling , to get all the enzimes in order , as theyre dormant .

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Ooooh .. The Marine version 6-66 is also for fishing gear protection.
So many ruined bearings etc. from Saltwater trips. I'll pick up a can and spray up both my travel reels before the Nicaragua trip . That and soaking in fresh water afterwards , as taught. Maybe a shot into the Norty's Switch gear too. Thanks.

Would help if we knew if original wiring harness, positive ground setup of changed by the rebuilder.

First confirm battery is good or connect a known good one like from your car etc as test. Confirm what disconnect black is from/to to know if it should be on neg batt post.
No front light could be an ign switch issue or if it has secondary lamp switch on the headlight shell? No lights anywhere could mean bad ign switch or perhaps blown fuse. Can bypass with some aligator clip leads to confirm. A test lamp and or multi-meter very helpful these kind of issues.

islanddave said:

Hello Guys,

I have a simple but disheartening problem. I have had my 1974 Commando in heated storage for three years, and due to dire financial circumstances I have to sell it. I went through everything to get it running again re full service, but when I put the fully charged battery in it it has no power to any lights. I vaguely remembered that when I took the battery out three years ago, that a black wire with a copper eyelet came loose from the harness. Presumably this wire went from the harness to the battery. I desperately need guidance from someone to get this bike running so I can sell it. I am in genuine need of someones help. I am able to follow direction, but cannot search through endless threads to try and diagnose this my self. I am aking for some genuine help. The bike is not a beater.......it is in wonderful condtion, and I am heartbroken for having to sell it.

I am located in St.Catharines Ontario Canada.....so if anyone local can assist it would mean the world to me and my family. I would be willing to pay someone local to diagnose. I do not want to sell a non running bike for fear of loosing so much money for such a simple problem. The gentleman who built the bike has retired and closed shop.

Thank you sincerely ,

David

Click to expand...

You say you have a fully charged battery, so we'll assume that. If standard wiring, you have a red wire to the + on the battery and a Brown with Blue stripe on the -, and that goes to an inline fuse - the other end of the fuse is still brown/blue and goes to the master switch. The if the red wire is bad or the fuse is bad or the brown/blue wire to the master switch is bad, all power is cutoff from the bike.

Otherwise, there are four positions to the master switch. All the way counterclockwise should turn on the taillight at least. From there, one click clockwise is off. One more click clockwise and you should have spark and your brake light and turn signals should work. One more click clockwise, everything should work. When sitting, the master switch can corrode. Turn it back a forth a bunch of times to see if it cleans the contacts up and the lights come on.

You can remove a turn signal bulb and use it for a test light. Strip both ends of a wire. Hold one end against the side of the metal of the base of the bulb. The other end of the wire goes to the + of the battery. By touching the center contact of the bulb to things you can see if there's power where you touch. The first pace to check is the - of the battery. Next, the brown/blue wire on the back of the master switch (have to pull the cover off). Don't worry, it will not shock you.

Let us know what you find. If you don't have standard wiring, email me a picture of the battery area: marshg@gregmarsh.com

A test light is cheap.

ashman said:

A test light is cheap.

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Not when "dire financial circumstances" is in play.

Did we lose OP?

Maybe in debtor's Prison ?