750ace.com

4winds · Newbie Joined: 01 Jun 2009 Posts: 3

I had all three of the above go out this weekend. I changed the fuse and it promptly blew again. I am not mechanically/electrically inclined. The point of having the bike was to save money. Not to constantly shell it out. Can anyone tell me where to begin diagnosing the problem? Any advice besides "take it to a shop" would be appreciated. Thanks

BugMagnet · Posted: Mon Jun 01, 2009 9:56 pm Post subject:

This would have to be the result of a short in the wiring someplace.

Did you replace anything on the bike recently? Or maybe even a while ago? Take the tank off? or add anything to the bike? You may have pinched one or more wires causing a short.

You pretty much have to go over it with eagle eyes and try to find the pinch, then replace the wire.

There is a color wiring schematic in the back of the Clymer manual if you have it.

A meter is your friend.

PlaneCrazy · Posted: Tue Jun 02, 2009 4:21 am Post subject:

First, what year is your ACE?

Second, which fuse did you change? I'm assuming it was the 15amp one for front turn signal, brake and meter lights??

If so, then do this....

1. go and buy a package of 15 amp fuses. You should be able to get like 10 of them for $5 or less. You'll blow a few of them troubleshooting this problem

2. That fuse powers the turn signal switch as well as the horn switch. The switches on the handlebars are common places to wear out and short circuit. Take the switch housing apart on the left handlebar (2 screws) and look at the turn signal switch and the horn switch .. especially the horn. See if it looks burnt or theres any arcing signs around them. You can also make sure nothing is touching the frame or a ground while you have the switch housing apart and then pop the fuse back in and power up the bike.

3. If you can't find anything in the switches, then you'll have to isolate where the short is...

1. remove all your light bulbs from the turn signals (4) and the brake light AND the license plate light. Then try another fuse. If it doesn't blow, then you start adding the lights back in one by one until one makes the fuse blow and report here which one did it.

2. If the fuse blows even with all the bulbs out, then unplug the meter housing on your gas tank. (4 recessed head screws to get cover off, then unplug the big connector under there.) If that works and the fuse doesn't blow, then you have a problem with that unit somewhere. Look at the wires and see if any got pinched against the frame or tank or something.

I'm leaning towards the horn switch since a lot of people have had that type of switch cause problems before.
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jmichael · Posted: Tue Jun 02, 2009 10:27 am Post subject:

This trouble shooting of this fuse is an interesting topic. I hope you follow Plane's advice and post back what you found!
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Everyone knows I am different....so what! Smile

Honda 2002 ACE deluxe
Honda 1969 K1 CT90 Trail

rojo · Gray Beard Joined: 26 Sep 2005 Posts: 352 Location: conn.

electrical problems are tough... especially a short. Removing the light bulbs may not help if the short is in the positive wire leading to the bulb. If the wire is shorted to ground it is completing a circuit and will still blow a fuse reguardless if the bulb is in place or not. You can use an ohm meter to try to find the short. With the ignition key off, Remove the bulb, and check for continuity from the live wire to ground, you should get a reading of "0" if there is no short. If you get a reading you found your short. Just make sure there is no other light or device connected to that line. Like PlaneCrazy said, you might want to check the switches that have been a problem for others first. I had a short in my system( believe the same circuit) and never did actually find it. In jiggling the wire harnesses I must of moved a wire enough to eliminate the short as it has not blown a fuse in a while. Smile

, but I'm figuring it will probably return sometime in the future .
In a way, you are lucky since the fuse is blowing as soon as you put the key on. Mine only blew when I would hit a bump making it harder to find.
You can also try finding the wire that feeds each item on that circuit and disconnect all. Again use Plane's method and replace one at a time until you get the fuse to blow. Most of the wiring connections are under the right side cover where the fuses are located.
Patience!!... and good luck! ... rojo

PlaneCrazy · Posted: Tue Jun 02, 2009 4:35 pm Post subject:

I agree that a multimeter is a good tool to use, but on a motorcycle, it can be misleading unless you have experience with electrical circuits. That's because you can get inaccurate readings unless you completely isolate each circuit. For example, you may remove one turn signal bulb and try to measure the continuity between the power lead and ground, but in fact, you may get a strange resistance reading because the path of the meter's current may run back through the circuit through another bulb somewhere.

Also, sometimes there can be a break down in the insulation of a wire that only causes problems when there's a load on the circuit. When you try and measure for continuity using a simple ohmeter, you'll get an infinite reading and think it's ok, but if you used a MegOhm meter (Meggar) then you'd see that there was continuity there while a current was present.

With bikes... it usually comes down to shit luck finding shorted wires, or simple troubleshooting like I suggested and even just shaking all the wire bundles one by one until a fuse blows. Over time, you'll start to learn the most common problem areas.

Finally... one common cause of a short on motorcycles, is a bulb filament actually breaking and stretching and falling down and shorting against the elements inside the bulb. Because they get glowing hot when on and the bikes have so much vibration, this happens a lot on motorcycles. And when you remove the bulb, it may shake the wire loose and voila! problem solved... you'd almost never know you even had a short. but a bulb may now be completely burnt.
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4winds · Newbie Joined: 01 Jun 2009 Posts: 3

Thanks for the info everyone. Plane Crazy, my bike is a 1999 750 ACE with 8500 miles on it. You are correct in surmising that I changed the 15W fuse that regulates the turn signals/horn/nuetral light. I've already replaced the turn signal switch a few months ago. I just began taking off the turn signal covers. It turns out that my turn signal bulb had separated from the metal base and one of the wires was grounding out the inside of the housing. Thanks for the help. I'll be riding it to work tomorrow so time will tell if it is fixed. Thanks, Patrick

jmichael · Posted: Wed Jun 03, 2009 8:01 am Post subject:

pesky bulb! Laughing

I'll bet the fix is done!
_________________
Everyone knows I am different....so what! Smile

Honda 2002 ACE deluxe
Honda 1969 K1 CT90 Trail

rojo · Gray Beard Joined: 26 Sep 2005 Posts: 352 Location: conn.

Good call PlaneCrazy! Ya nailed that one!
experience is golden!! Wink

rojo

thACE · Posted: Thu Jun 11, 2009 4:44 pm Post subject:

Now lets all go and change our bulbs out/ clean the lens! This way we will have less problems this riding season.
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Pray, Ride often and Speak the truth; everything else will only be in your mirror.