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Discussion Starter #1
Hello,
I recently purchased a 1980 Honda CX500. My Second bike was a CX500 but I only kept it for a year. Most of my bikes are Suzuki's.
I have installed a new battery and starter relay but nothing happens when I hit the starter button. The head light dims right out but that's it. If I bridge the relay the starter cranks. I'm stuck as to where in the wiring I should start looking. It had sat for a couple years and the last owner installed a new clutch cable. I've cleaned all the connections that seem related to the starting system. I opened up the right hand handlebar switch and everything in there appears ok. I checked the neutral switch under the engine and cleaned the connection there as well. I bridged the wires for the clutch lever switch and still nothing.
What am I missing?

Pete
 

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Have you tried pulling in the clutch lever? I assume you get a green neutral light. The safety switch at the lever may be bad/sticky. I have that issue on occasion. The free FSM link in my sig line is required reading and contains wiring diagrams.
 

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Discussion Starter #4
Hi Pete, thanks for the welcome. I have been pulling the clutch lever in as its a requirement on Suzuki's as well. Still nothing happens. Yes I have the green neutral light..
 

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Disconnect the yellow red wire at the solenoid and with a jumper from the battery positive apply 12 volts to the terminal on the solenoid where the yellow/ red wire had been attached. If that gets the starter working then you know the solenoid is functioning properly and to look in the wiring to and from the start button.
 

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Discussion Starter #6
I just installed and brand new Honda Solenoid. It didn't make any difference.
 

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You need a voltmeter or at least a test light. Start following the voltage from the battery to the key switch, to the start button, to the solenoid. There must be an open circuit somewhere. The fact that the headlight goes out when you push the start button shows that that side of the switch is working properly.
 

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Not likely the kill switch circuit as the starter won't engage. The kill switch circuit won't keep the starter from operating.
 

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Discussion Starter #10
The PO said he did install a new clutch cable and Im wondering if he damaged the clutch switch while putting the new cable on. Its just a thought.
 

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I bridged the wires for the clutch lever switch and still nothing.
What am I missing?

Pete
This pretty much rules out the clutch switch.

Where are you? There may be another member near by who could help?
 

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Discussion Starter #13
I also work at a motorcycle shop in Guelph. Just been off this week so I havent been there to pester the techs...yet
 

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I'm always up for a ride to get to 6 feet from a fellow CX/GL owner. :D
 

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Have you tried not to connect the wires at the clutch switch?
I can’t remember at this moment and I’m at work so I can’t check if the system will start when grounded or the other way around. I know the kill switch will shot the system by grounding the CDI, assuming your bike it’s a CDI.
 

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The Start button has 2 sets of contacts, one to apply power to the solenoid's coil and the other to interrupt power to the headlight so that the battery's full power is available for the starter motor. It is very possible that the contacts that send power to the starter are dirty.
The easiest way to clean the contacts is to spray electrical contact cleaner into the hole right below the button and work the button a few times. You may need to repeat that several times before it starts to work and in really stubborn cases you may need to disassemble it and clean the contacts with contact cleaner and an old toothbrush.
Note: Real contact cleaner is required for this, not something like WD40. And NEVER use sandpaper in an electrical contact because particles of grit can become embedded in the soft copper and cause more damage.

This might help:
If jumping the stud terminals on the solenoid makes the starter motor run it is safe to say that the battery, starter motor and associated cables are all OK. If the main fuse is OK too the next thing to look for is power to the solenoid's coil by measuring the voltage between the yellow/red wire and the green/red at the solenoid when the Start button is pressed (key On).
  • If something close to 12V is present there and the starter doesn't operate it is possible that your replacement solenoid is defective.
  • If there is no voltage (or very low voltage) there something is wrong in the circuit. This time measure between the yellow/red and any green wire (green wires are ground/common on all Honda motorcycles) while you press the Start button (Key on).
--- If there is no voltage (or very low voltage) between yellow/red and green the problem is in the circuit that feeds power to the solenoid's coil (keyswitch, Start button &c).
--- If you have voltage between green and yellow/red the problem is in the circuit that connects the solenoid's coil to ground. The solenoid's coil can ground through either the diode (located inside the fusebox) and neutral light switch or through the Starter Disconnect Switch in the clutch perch. If you get this far without solving the problem let me know and I'll give you instructions for the next step.
 

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Hello I'm new to the forum. I bought my 1980 CX 500 last week. Without a battery. I was sorry to see that when I jumped my battery leads from another bike, everything worked except the starter motor. I check the fuses and took apart the handle bar perches to make sure they were all plugged in and sound. But that didn't lead to anything.

I however got extremely lucky and was texting the button with another battery and the starter motor sputtered off and on.

Immediately after that happened I went to Napa and got some contact cleaner to shoot up the hole under the starter button like recommend by Sidecar Bob and now it works like a charm.

TLDR: Shoot contact cleaner up the service hole under the starter button!
 

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BTW: Welcome both of you to the forum. Please add your location to your profile and your bike's model and model year (NOT year first registered) to your signature so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel because old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet. If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid).
 

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Discussion Starter #19
I will try squirting the contact cleaner through the hole first. If that doesn't I will start checking all the voltage checks and see where that leads too.
Thank you to everyone who is helping out with different leads. This is the big reason why I joined!
Mike I would be happy to meet one day so you can see my ride and give some ideas on it.
 

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Discussion Starter #20
Great news this evening everyone!! After spraying the contact cleaner into the hole under the starter button and working it many times, I connected the battery, turned on the ignition and hit the starter button and it it cranked over like it was new!!! I was sooo happy to hear it cranking over. I shot a bit of quick start down the air box and it started right up smooth as ever...for 3 seconds. LOL
But thats great news cause I checked the fuel petcock and it was shut off. No bad fuel leaked in to the carbs or sitting in them...The guy knew how to store it! Next step, drain the tank and remove it and see how it runs on an iv bottle.
Thank you so much to those that mentioned that little hole and contact cleaner. Thats all it needed. One Very Happy CX Owner now. :):):):)
 
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