Honda CX 500 Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter #1
So I've read a lot of the threads on here about sorting out electrical problems, but need a bit of guidance on ignition switch problems, and can't find much diagnostic stuff.

My main fuse blows out the instant I turn the ignition to on. I've rigged up an LED across the fuse gap, which stays lit as long as the ignition is at the on position. I've checked all the lines for fraying, and found nothing (including inside the headlamp). I've removed all of the components, and the only one that stops the LED across the main fuse is the middle component next to the battery, which I believe (following the wires and colors, red and red-white stripe) leads to the ignition. When I detach the ignition and reconnect the one next to the battery the LED goes out too, but this is presumably because the circuit can't be completed with the ignition detached?

If this is right, then either a) the short is in my ignition, and I need some help working that out or b) the LED is just stopping because the ignition isn't connected, and the problem is somewhere else. As y'all know, electrical stuff can get pretty aggravating, so my sanity would seriously appreciate your input... What am I looking for in an ignition short, and how do I get into that nasty metal tube?

Thanks in advance

Thom
 

·
Registered
Joined
·
292 Posts
Thom, try disconnecting your other fuses and then see if main fuse blows. This will help in the process of elimination to determine what circuit is shorted. If main fuse still blows then unplug ignition switch connector and try again by using a jumper wire to go from main hot wire [red] to each other wire one at a time at harness connector. If possible DURING TESTING ONLY replace main fuse with a circuit breaker 30amps [available at auto parts store] , this will pop out when shorted then reset after it has cooled down- so you don't have to use several fuses for diagnoses. Also, visual inspection is going to be your most effective diagnostic technic , so get a bright shop light or flashlight to help. Process of elimination until fault is found, then repair as necessary.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #4
Thanks for your quick responses.
Fega, what's the difference with an LED bulb? It seems to recognize the broken circuit ok? I don't have an incandescent lying around right now.
Francois, I have removed the other fuses so I know it's not those circuits (I thought it might be recently disconnected turn signals, but they make no difference). Could you elaborate on the jumper wire test? So I clip into the red cable on the harness and take it to each of the connections on the ignition's harness until the light goes off? And if I find the fault in the ignition what do I do?

Thanks again
 

·
Registered
Joined
·
292 Posts
I was suggesting to replace the bulb at main fuse with a circuit breaker so that you will know when you do or don't have a short to ground. You can test ignition switch internal connections to ground with a multimeter on each lead [disconnected] to switch mounting screws- should be infinite ohms on all wires with key in all positions. .
Uncertain about what tools you have available and what your experience is so included a basic video. If you don't have a multimeter you can find them very inexpensively for this purpose at any hardware store.
 

·
Super Moderator
Joined
·
15,331 Posts
Any chance the brown wire in your headlight bucket is touching the housing? If so it will blow every time. Also is your ignition switch original? Some aftermarket ones don't connect the right wires.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #7
Thanks, my experience with the electrical stuff is next to nil so guides like that are helpful. I checked for problems in the headlight bucket and can't see any. My ignition is original.

So I get a multimeter, check the resistances across the mounting screws? As in the bolts that hold the ignition tube in? Is this where a ground would go if there was a problem in the ignition?

Sorry for the high level rookie simplicity needed here
 

·
Super Moderator
Joined
·
20,808 Posts
Try disconnecting the ignition switch and making a shunt wire to bridge the red and solid black wires. This will give you basic ignition function. See if the fuse blows like this. If not, the switch or the brown accessory wire Blindstitch mentioned may be at fault.
 

·
Registered
Joined
·
41 Posts
If you replace the main fuse with a 12V LED bulb you have a bright ignition light only. Replace the fuse with a normal (headlight) bulb and you have a tester. Full bright - short somewhere, less then full bright - no short to ground.
 

·
Super Moderator
Joined
·
15,331 Posts
Is this where a ground would go if there was a problem in the ignition?

Sorry for the high level rookie simplicity needed here
The ignition isn't grounded. It's just a switch that completes a circuit.

Connecting the black and red wires makes it live.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #11
Excellent stuff guys. Will get back to you tomorrow after I've had a look.

This forum is rad.
 

·
Registered
Joined
·
3,803 Posts
Thom, if you need some help with testing you can PM me as I am close by.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #13
More help needed. I've really lost track and gotten confused about what I'm trying to do. Here's my situation at the moment.

I've got a circuit tester light (automotive specific) rigged across the main fuse gap. When I connect the two sides of the bulb into the main fuse gap with the ignition on, the bulb is full bright. When I disconnect the negative and take that connection to the connector on the ignition that I've pulled out, all of the cables (brown, black, green) except red and black-with-white complete the circuit and turn the bulb full bright.

When I connect into the red and the black-white-stripe there is no light on the bulb. I've lost track of what this means. Does it mean there isn't a grounding fault on the live red wire between the battery and the ignition, because otherwise it would light up? Should I be connected to the negative end of the battery for checking circuit problems? I'm really stuck.

Help thus far much appreciated.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #14
Just saw your reply OCR! Thank you. Maybe this weekend if I can't get it sorted. I wouldn't want to waste your time on it until it's definitely not rookie stuff.
 

·
Registered
Joined
·
41 Posts
I've got a circuit tester light (automotive specific) rigged across the main fuse gap. When I connect the two sides of the bulb into the main fuse gap with the ignition on, the bulb is full bright. When I disconnect the negative and take that connection to the connector on the ignition that I've pulled out, all of the cables (brown, black, green) except red and black-with-white complete the circuit and turn the bulb full bright.
Hi!
Just use a high W bulb (headlight). 12V 55W/60W or similar. The higher W is better.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #16
Ok, I have located an issue.

After messing around with the electrics for an hour or two, I got it briefly to a point where a fuse wouldn't blow immediately with the ignition turned to on. I then commenced trying to mess that up.

I managed to blow the fuse by messing with my left hand controls. Something seriously funky is happening here. I turn the ignition, the oil light comes on. I try the left signal - it flashes fine. I try the right signal, and the OIL light starts flashing, and nothing happens with the right turn! The oil light flashed for about ten seconds pretty fast, and then the main fuse went.

Now here's where it gets even weirder. I unplug the flasher unit. I wire the light back into the circuit in place of the main fuse. I turn the ignition, the oil light comes on, and the main fuse bulb is only half lit (this is the first time this has happened). I decide to check the neutral light, put it into neutral, and the main fuse light lights up fully like a Christmas tree. Does this mean I have a cable messed up somewhere in my neutral light wiring? I've no idea what is going on at this point.
 

·
Registered
Joined
·
6,622 Posts
Have you tried disconnecting systems like signals to see what happens? It sounds like your wiring is not connected properly. There is a wiring diagrams on the wiki. Also SidecarBob has a system color code somewhere on forum. Check inside headlight for weirdness. It's all color coded.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #19
More problems.

I got about a week's riding out of the bike by removing the bulb for the neutral indicator and bridging the front signals (those lights were removed after I smashed the bulbs up). This annoyingly meant my rear signals ran as running lights but I was going to sort that out later once I was sure the bike was running okay. Sure enough today it died again and I had to bump start to get home.

So the current situation, which I'm trying not to think of as an unstoppable deterioration, but it's starting to feel that way, is this. My neutral bulb is removed. All other electrics were working fine, until today. Now, when I turn the key, the oil and the signal lights come on as usual. I press the starter and everything goes out. I turn the ignition to off, then on, and the lights are still out. I wait a minute. I turn the ignition on and the lights are back. I press the starter, everything goes out, nothing happens. Rinse and repeat.

It was really easy to bump start, and all of the lights were back. When I used the turn signals, they flickered rapidly and unevenly (I really hate turn signals lately - I will just get rid of them soon), so the flasher (an LED model, but rear lights are still bulbs, I was planning an upgrade) may be part of the problem.

This is newly worrying, as none of the fuses are broken. Any ideas what's happening? If I can bump start the bike do I need a new starter solenoid or starter engine?

Any help as always much appreciated. I'm increasingly in over my head here.
 

·
Registered
Joined
·
292 Posts
How did you stop the main fuse from blowing? Are you certain that all your battery connections and cables are tight?
 
1 - 20 of 24 Posts
Top