Topic: Bike not starting after installing new bars.

[itskohler]

Hello all, hoping to get some guidance and wisdom from you all. So last week I received my clubmans in the mail and immediately went to install them. I knew I would need to run the wires through them so I went about cutting my holes, etc. When it came time to actually remove the old bars with the switches and all, I unpluged all of the wires in the back of the headlight, thinking it would be cake since they are color coded...Well, I can't get the thing to start, headlight wont work, blinkers are a no go. It turns over when I push the button but it wont actually start. Is there something I am missing here? I sat with it almost 8 hours total retrying the wiring, but with no luck.

[mystic_1]

Time to pull out the voltmeter and start probing around, methinks.

What bike, btw?

Were all of your bullet connectors in good shape, not corroded, etc?

Off hand, the thing that's common to the headlight, kill switch, and blinkers, is the Black wire that provides power to them all. I'd start looking there.  The starter button runs on a separate circuit.

Do you have a wiring diagram for your bike?

mystic_1

[LesterPiglet]

Wiring is a piece of cake. Disconnect everything in the bucket and start over. Do one circuit at a time and you will get there. Start with the main wiring that lets the bike run.check for sparks at the points when you think you've done this. Then move on to tail light. Make sure it works, as well as brake light. Move on to the headlight circuit then indicators etc. Any order you like but check they work before you make any more connections. You DO have a wiring diagram?

[itskohler]

Sorry, should have stated that. It's a CB500, K2.

I have pulled all of the wired out and redone it over and over and over. Good to know about the black wires, as there are a few of them and I was pretty confused about what goes where.

All I have is a wiring diagram from here, as well as the Clymer.

[wjustinleigh]

Check near the holes where the wires go through for damaged wires which could be causing grounding problems.  The controls themselves have to ground to the bars properly too.  The originals have a pin that goes into the bar which keeps it aligned properly but also makes sure it grounds well.  You probably had to pull that pin out, which is fine as long as you still have a good ground contact.  If the bars are painted you may have to scrape off enough paint where the control clamps onto it so the control can make contact with the metal in the bar.

Having recently wired and rewired a couple headlight buckets I'd agree with Lester - unplug everything, make sure power goes to the ignition then from the ignition to something simple like the horn, make sure the horn works.  I like the horn because it doesn't involve indicator lights or anything.  Then do the blinkers, brakes, headlight, etc.  One at a time so you know what works and what doesn't so you can find a ground problem if it arises. 

This is a really good site I used to wire mine:  http://oldmanhonda.com/MC/wiring500.html.  It allows you to isolate what you're working on as you step through it.

[itskohler]

Ok, I will try again when I get home. I like the idea of doing the ingition first, then going through everything else. I drilled the holes for the grounding pins and its maybe .2mm bigger than the pin itself, so its making good contact. Thank you for the link as well, seems like a perfect match for what someone with my level of knowledge needs with this stuff.

[mystic_1]

In case this is a different diagram than the one you already have...

[itskohler]

Beautiful, thank you.

[itskohler]

The wiring diagram helped out a bit, but I ran into a snag...again. I went to start the bike and the nuetral light flashed 3 times then completely dead. No lights, horn, nothing. I'm assuming it is the 15A fuse off the battery, does that sound right to everyone?

[mystic_1]

Blown fuse is not a "cause" it is a symptom.

Sounds to me like you have a short somewhere.

When you drilled your new bars and ran the wiring, did you chamfer the rough edges of the holes to avoid slicing up the wiring's insulation?

mystic_1

[itskohler]

I smoothed them out as best I could. Can't speak to the welded joints however. So about to take a shop, I can't figure it out and I'm reaching my limit on what I can do.

[mystic_1]

Did you follow Lester and wjustinleigh's advice to unplug everything and then wire up one circuit at a time, testing as you went?

If everything was working properly and the fuse only blew when you pressed the starter button, that suggests that your short is in the starter circuit itself.

mystic_1

[calj737]

If your neutral light is flickering, it's a sure sign of a poor "ground". The stock wire color of GREEN is always ground on a CB. It's also possible that the instrument light for the neutral is buggered beneath the handlebar clamp.

Do you have a multimeter?

[evanphi]

I smoothed them out as best I could. Can't speak to the welded joints however. So about to take a shop, I can't figure it out and I'm reaching my limit on what I can do.

You're not at your limit just yet. Wiring is simple.


Try pulling everything out of the bars and starting again. Attach the controls to the bars with the wiring OUTSIDE first. If you take it out you might see something got scraped/scratched/bare. Then do the hookups and voltage checks again, and LABEL IT ALL!!!!! before you unhook it. I love the colour coding that Honda gave us, but sometimes you need to write the names on little bits of painter's tape.

[itskohler]

Did you follow Lester and wjustinleigh's advice to unplug everything and then wire up one circuit at a time, testing as you went?

If everything was working properly and the fuse only blew when you pressed the starter button, that suggests that your short is in the starter circuit itself.

mystic_1

Yes, I did do that. I don't know if that process is a common knowledge that I was unaware of or anything, but it made it so much easier.

If your neutral light is flickering, it's a sure sign of a poor "ground". The stock wire color of GREEN is always ground on a CB. It's also possible that the instrument light for the neutral is buggered beneath the handlebar clamp.

Do you have a multimeter?

No, I do not have a multimeter. Could it be the green wires inside the housing of the headlight that might have come loose? I dont think its just the light, those are working fine. Switched it with the high beam light that I know was working fine and still nothing.

I smoothed them out as best I could. Can't speak to the welded joints however. So about to take a shop, I can't figure it out and I'm reaching my limit on what I can do.

You're not at your limit just yet. Wiring is simple.


Try pulling everything out of the bars and starting again. Attach the controls to the bars with the wiring OUTSIDE first. If you take it out you might see something got scraped/scratched/bare. Then do the hookups and voltage checks again, and LABEL IT ALL!!!!! before you unhook it. I love the colour coding that Honda gave us, but sometimes you need to write the names on little bits of painter's tape.

This will be my next step. Pulling those wires is a huge pain in the rear. I kinda followed the suggestion from another post using fishing line in a coninous loop. Maybe if I do that I will pull through certain circuits at a time until the last one is done. But this is a last ditch effort.

[mystic_1]

Woah, I wouldn't pull the wiring out of the bars, until you've confirmed the location of the problem.

First:  Is the fuse blown?  If so, replace it.

Second:  Disconnect (unplug) the wiring for JUST the starter button, and test everything else.

Let us know.

mystic_1

[calj737]

Mystic has some good recommendations, but you need to get a multimeter to evaluate what and where your problem is.

Yes, you can unplug, replug everything one at a time. However, visual inspection is seldom as reliable as a meter. You ned to be methodical, and begin at the beginning. Check the voltage of the battery. Having charged it and now believing it to be good is insufficient. Put a meter on it. Then, check the voltage at both sides of each fuse, front and back of the fuse block.

Then proceed to the right side control block. Unscrew it, and use the meter to read the voltage present when the key is switched on. If you aren't getting 12v to the handlebar, nothing will work reliably. Then you move circuit by circuit to identify where the voltage drop is.

It's likely that when transferring your controls you inadvertently pulled a wire loose from these 40 year old controls, but you must identify which/where that ofcur by a meter to be 100% certain. Else you are on a game trail in the dark without a clue. You may encounter your quarry, but not likely.

[mystic_1]

Lacking a multimeter, you can construct a test light using a 12V lightbulb such as a turn signal bulb.

Wire up the bulb to a couple of long wires.  If you have a socket for the bulb, that makes this part easier, otherwise you can solder the wire to the bulb or just wrap it and tape it.

To test for +12V on a  circuit, connect one wire from the test light to a ground point on the bike, then touch the other wire to the circuit you are trying to test.  You can connect the wire to a pin and push this through the insulation of a wire, if you need to.

To test for connection to ground, connect one wire from the test light to the positive terminal on your battery and then touch the other wire to the circuit you are trying to test. (this assumes that your battery's negative terminal is properly connected to the bike's ground cable).

mystic_1

[itskohler]

Woah, I wouldn't pull the wiring out of the bars, until you've confirmed the location of the problem.

First:  Is the fuse blown?  If so, replace it.

Second:  Disconnect (unplug) the wiring for JUST the starter button, and test everything else.

Let us know.

mystic_1

I believe the 15A fuse is blown. Its behind a few things on my bike, but I can see that the clear plastic casing has melted. Pretty good sign that the fuse is a goner.

[wjustinleigh]

I've blown a couple fuses a simple short probably won't blow it, you just lose power.  If you have a good short or something significant you'll blow the fuse.  To completely melt the fuse holder you've got something else going on.  Either there is a bad wire in the fuse holder (I've had this) or something is connected to something very wrong.  The fuse holder is probably 40 years old with brittle wires and bad connections.

I agree with evanphi, you've got this - wiring feels overwhelming but gets under control really quickly.  I wouldn't pull the handle bar wires yet either, they're a pain and pulling them in and out causes more damage.

First - Get a simple current tester, they're about $6 from any auto or home depot, have a clip that you attach to something metal and a long pokey attached to a light.  You can poke through insulation if needed to check a current and easily get up into a connector.  Light goes on, you're live.  This is important, I used it probably 50 times during the last wire-up.
Next - Get a new fuse holder w/fuse, another $5 from any auto store.
Then - Unplug everything in the headlamp and walk through each circuit one at a time.  I really recommend the horn first, it's isolated to one control and the horn, it's super easy to see the wires all the way through.  If you can't get current to the horn trace it back to the ignition switch, make sure power is going in and coming out.  If that works now you know you're good from the battery through the ignition switch to the headlamp and you can move onto the blinkers - same control plus the indicator light.  If that works you can move over to the other control with the lights then the start button and start/stop switch.

It would be really nice to pick up some terminal connectors so you can hook up the new fuse properly and replace any bad connectors with new ones, but you can get by with just electrical tape.

All in you'll have spent $10 and two hours vs. $200 at the shop and who knows how long to get your bike back.

[itskohler]

I called a shop to have them sort this, and a few more gremlins out that I have had. So hopefully it wont cost an arm and a leg. The shop owner has a mechanic that is "an avid lover of the SOHC Hondas" and knows his stuff. I need my brake cable shortened, an oil leak sourced and stopped, and of course the electrical.

I want to do this all myself, but this will soon be my only transportation for a long time to come and need to know that it will be reliable. I don't trust myself for that haha, not with electronics at least.

[madmtnmotors]

You can get a functional multimeter for $10. If I had to pay a mechanic to do everything I've had to do I would have thrown in the towel (gone broke) a long time ago.

Are your handle bars painted? Did you paint the top of the triple tree where the bars clamp down? Several of the controls are grounded through the bars...

and paint makes a terrible ground.

[itskohler]

I sanded the bars down where they made contact with the triple tree just incase they needed to be grounded there, glad to know that they do.

I went with the shop purely for electronic fixes. I can do everything short of welding at the house and feel confident in my ability to do so.

[madmtnmotors]

I sanded the bars down where they made contact with the triple tree just incase they needed to be grounded there, glad to know that they do.

Does that mean they are painted? The controls themselves also have to be grounded to the bars too...

Controls>Grounded to bars>Bars grounded to frame (via top triple clamp)

[wjustinleigh]

That's easy to check, just run a wire from one of the screws in the control the frame somewhere.  If it's OK then you have a grounding issue.  He drilled a hole for the control pin so it should be making good contact even though the bar is painted.