Hey, I have an electrical issue and I'm hoping someone can point me towards a solution. I'm lost when it comes to electrical issues. My bike was running great for years and then seemingly out of nowhere, it has begun blowing the fuse (the one next to the battery and I think the only one on the bike) as soon as I turn the ignition switch to on.
Based on the googling I've done I think I have a short somewhere. I tried a technique I saw someone suggest and wired up a 6v lightbulb where the fuse should be and have tried to go through the wiring system disconnecting wires and looking for the lightbulb to turn off. I did find a spot where the lightbulb turns off: If I disconnect the red wire from its connector just before it enters the ignition switch. I don't know if this is actually important or not and I can't figure out from the wiring diagram what this wire is doing once it enters the switch.
If anyone has any ideas I would really appreciate it!
CA160 blows fuse when ignition switch is turned on
Shortfrollie,
I understand your frustration as electrical issues can be a pain. If your fuse blows as soon as you turn your ignition on, it could be anywhere the 12 volts travels too; 1) headlight 2) tail light-especially where the wires pass through the fender. 3) horn 4) rectifier 5) lighting switch 6) coils You get my point. First, check your harness for pinched wires. In the headlight bucket, tail light wire routing, under the tank, seat etc. Sounds as if you haven’t a manual, so wire identification is tough. Eliminating the obvious “easy stuff” will narrow your trouble down. Disconnect the easy stuff #1,2,3&6. The trouble could also be inside the actual switch (horn, hi-low beam and starter). Whatever you do do not put in a higher valued fuse. This is not the easiest way, but minus a diagram, it’s a process of elimination. Thank you for the reply! I will keep an eye out for pinched wires.
I have a manual with wiring diagram for a CA95 and I'm hoping that the wiring is the same as a CA160. To eliminate the rectifier as a potential cause I was going to order one of these: http://www.oregonmotorcycleparts.com/rectifiers.html I have a feeling it might be the ignition switch itself but I can't figure out how to remove it to look inside. Have you ever had to remove it? It has two pieces that screw together with the headlight bucket in between. The chrome piece outside the bucket has two small notches that look like they might have some use if I had a special tool. I vaguely recall that it was loose at sound point and I might have put locktite on the threads. Really regretting that now. Anyways, thank you for the help and I will look into all the 6 points you suggested. Blown fuses.I'd wait a while before spending money on a new rectifier. In most 60's Hondas the rectifier is connected to the battery all the time, not just when the ignition is switched on. (That's why the batteries run down after a few days) In my experience the fault is unlikely to be the rectifier.
If your bike has the tubular handlebars I'd start by checking the wires that run through them, especially where they enter and leave the bar, a 'popular' place for chafing the insulation leading to blown fuses. Be methodical and check one thing at a time by disconnecting as much as you can and then reconnecting them in stages until you find the culprit. Your problem could be worse, at least you bike blows fuses straight away when you turn on the ignition. One that only blows fuses occasionally can be much harder to sort out!
I’m with DJM on holding off on ordering parts right now. Looking at the diagram on the net, the CA160 has one red wire and one red/white trace wire at the positive terminal on the battery, along with the cable to the starter circuit. (There is a high power relay there for the starter motor). The red/white goes to the rectifier. Disconnect that one and the starter wire, and see what happens. The red wire goes straight to the IG switch. I don’t think you can open it up with any margin of success, so use caution.
Type in “wiring diagram CA160” on a google search, and you’ll find your colors. Thanks guys. I had more time for troubleshooting and discovered some things. First off, I did take apart the ignition switch and I should have heeded your warning on that. If anyone is reading this I would not recommend taking it apart. There are ball bearings and small springs inside and it's not fun putting it back together. I didn't see anything inside that looked important but I did get it back together.
G3, I did disconnect the red/white wire and starter wire and it did not cause the lightbulb to go out (the one I have wired up to where the fuse should be). So I'm thinking you both are right that it is not the rectifier. I was going to take off the handlebars and I probably still will but I found a couple places around the horn and the ignition coil that cause the lightbulb to go out when I disconnect them. Here's a few photos of those wires: https://imgur.com/a/4V2Ky First photo: If I disconnect either the black or green wire here the bulb goes out. This is right underneath the air filter near the battery (I have the air filter removed to get at the wires). Second photo: These wires both go straight into the ignition coil from the first photo. Third photo: If I disconnect the green wire here that goes into the horn the bulb goes out. I'm not sure if this is the same green wire as in photo 1 and 2 but I think it is. I still can't find a wiring diagram that perfectly matches my bike. So if I disconnect either of these 3 points, the bulb goes out. When I have one disconnected I can press the electric start button and I hear it start to fire, which doesn't happen at all with the wires connected. I think it's possible the bike might start like this but since I don't understand what the wires are doing I didn't want to really try it. I'm wondering if the horn is the problem. When I press the horn button with the wires connected, the horn barely makes any noise. But why does the green wire seem to go from the horn to the ignition coil? And why would the electric start still seem to work with a wire disconnected from the ignition coil? Wiring issues.Can't answer all of these but from your pictures the wiring and the connectors (at least the ones you've shown us ) look very good for a fifty year old bike.
If your horn is making any noise at all it's unlikely that it is the cause of the blown fuses. Reasons for weak sound, partially discharge battery, lose or dirty snap connectors either in the horn or inside the headlight shell, corrosion on the actual horn push button or the horn itself needs a 'service', IE Clean and adjust the internal contacts in the horn itself, the domed cover should just pop off if you're careful. The starter circuit is totally independent of the ignition coils so no surprise that the starter motor works with a wire off the coil.
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