Troubleshooting & Emergency Roadside Repairs
Eventually, every motorcycle owner has a problem with their bike's electrical system. If you are lucky, it's a simple problem that happens in your driveway that you can get your dealer to fix. However, we should all be prepared for problems happening on the road, when we are far from any garages and their help. I'll try to offer some basic troubleshooting tips here as well as techniques for repairing those problems on the side of the road, so you can get the bike back home.
There are some basic things you must know before you can troubleshoot an electrical problem. First, all circuits on a motorcycle have four basic requirements... Power Supply, Conductor, Load and a Switch.
Power Supply is the battery. It is NOT the alternator! All power for all systems on a motorcycle comes directly from the battery. The alternator is only used to charge the battery and prevent it from becoming depleted during normal use.
Conductors are the wires
Loads are the devices that actually consume electricity to operate. Examples would be a light bulb, starter motor, horn, etc. All circuits have a load. Even if you just jumpered two wires across a battery, then the wires would then become the load as well as a conductor and they would consume electricity to produce heat.
Switches are the devices used to control the circuit. They can be mechanical (ex: turn signal switch) or electronic (ex: transistor)
Next, there are three unwanted circuit conditions that we will run into on our motorcycles. They are Open, Shorted and Grounded. It is important to learn how to recognize what type of failure you have in your electrical system.
An Open circuit is one where the power does not reach the load. Usually caused by an open fuse, broken wire or a faulty switch
A Short Circuit is one where the power is 'shorted' to ground before the load. This usually results in a blown fuse or circuit breaker. It can be a wire that is cut or chaffed through and shorting to the frame or, again, by a faulty switch. Sometimes it can also be a sealed electronic unit that has failed internally, causing a shorted condition. Examples of this would be a sealed turn signal relay, starter solenoid or ICM box
A Grounded Circuit is one where the power is shorted to ground after the load but before the switch or controlling device. So the load may be powered (light on for example) but there is no control over it.
There are two basic tools that can help you troubleshoot almost every electrical problem
the multimeter and the test light. A test light is nothing more then a 12 volt light with two leads that allows you to quickly and easily check for power in a circuit. The multimeter can also do this, but it has many, many other functions. It can check continuity, test diodes, measure resistance and check for bad grounds, measure amperage draw
the list is endless. And these days, you can buy a really decent multimeter for very little money.
Make sure to read the instructions that came with the multimeter before attempting to use it on your motorcycle. Here are some basic guildlines for the use of multimters in troubleshooting...
Always remove all power from the circuit you are measuring
Remember that electricity can have several paths, so if you are measuring for resistance or conductivity, then you need to make sure that what you are measuring is isolated from the rest of the electrical system. Figure out how to do this by removing a fuse, disconnecting a wire or some other way
Use the OHM setting on your meter and adjust the scale as necessary to get a reading that is as high as you can display on the scale you have selected. (Ex: don't read 100 ohms on the 2000 ohm scale, if you have a 200 ohm scale available)
Always turn off the meter after use, or you can drain the internal battery
For most measurements, you will be using the DC scales. The exception to this would be if you were measuring the output of the alternator phases, where you would use the AC scales
Always pick a scale higher then the anticipated voltage you expect to see, then reduce the scale down to were you get the most accurate reading
Be very careful not to touch the leads to yourself, other wires and/or the bike's frame
DC Current Measurement:
To measure current, you MUST connect the leads in series with the circuit. This will involve breaking the circuit in some way so you can connect the meter. DON'T ever try to measure current by placing the leads across or in parallel with a circuit. This can damage your meter
There are usually two plugs that you can connect your red lead too when measuring current. The one that you measure resistance and voltage on is usually used for low current measurements (mA's) while the separate red plug is for higher current measurements, and usually is in the 10amp DC range. Use this one for large current measurements like starter loads. Failure to use the proper scale and plug can result in a fuse being blown inside the meter
Emergency Roadside Repairs
Sooner or later, you are going to run into an electrical problem with your motorcycle while you are on the road. With a little preparation and planning, you may be able to deal with the problem yourself and avoid the call home for a ride.
First, evaluate the situation... If it's just a turn signal burnt out, then you can probably continue your day's ride and just use hand signals till you get home. If it's your headlight, then see if the high beam still works and use that until you can get it replaced. However, it's something causing fuses to blow, or a drain on your battery or your starter won't crank, then you are going to have to deal with it.
If you are planning on traveling more then an hour's drive away from home, then you should carry a basic toolkit on your bike. In addition to the normal tools you would have in your tool kit, I would recommend the following for electrical roadside repairs...
Black electrical tape
spare headlight bulb (wrapped in foam to protect it)
one each - 1050 bulb and 1057 bulb
combination wire cutters/strippers/crimpers
An assorted selection of solderless crimp connectors
tie wraps (also known as zip ties)
simple 12VDC test light
small LED flashlight to see at night or into dark areas of your bike
Printed copy of your bike's wiring schematic (laminated is nice!)
With just these few items, you will most likely be able to deal with 90% of the problems you might run into with your electrical system on the road. Everything listed above would easily fit in a waterproof ziploc bag and take up very little space in your bags. And, because they are so cheap now, you could add a small electronic multimeter to your kit for only $15 or so.
Unfortunately, motorcycles are designed to a very strict tolerance. It's a balancing act for the designers to make a package that looks good, falls within a certain weight, produces a certain horse power and has all the bells and whistles that consumers want these days. What that means is that the bikes we receive usually have very little extra capacity for additional electrical loads. These are not big one-ton trucks with 20 pound alternators that have gobs of excess capacity. So we have to be careful when making modifications or additions to the electrical loads on our bikes.
Calculating the Total Electrical Load:
To figure out the capacity of a bike's electrical system, you basically just have to determine what the output of the alternator is and compare it to all the loads on the bike. However, it's never that easy. First, the output changes as your speed (and therefore RPM) changes and the loads are not always constant.
So all we have to do now is figure out how much of a load any new accessories we add are and then see if the bike has the excess capacity to handle it. We also have to examine the rpm/speed/geard ranges and try and determine a "profile" of our own riding technique to determine what sort of average output we have during the conditions we do most of our riding.
Just remember that at idle, as mentioned before, we have a lot lower output and will actually be draining the battery, so it's a good idea not to idle for long and/or reduce your load (switch off those Aux. Lights, for example)
Disclaimer: The information contained in this and the preceding posts is condensed from the combined wisdom of the members and contributors of the Orange Crush Forum. The contributions are reprinted here exactly as posted by the contributors. The spelling, syntax, grammar, etc have purposely not been corrected in order to retain its original flavor. The contributors are from throughout the World, and English may very well not be their native language. Don't be an ass and complain about the lexicon. It is mostly subjective, with a little objectivity thrown in for seasoning, based on the experiences of the contributors. Use this info at your own risk. The site owner is not responsible for its accuracy or validity. None of the procedures described should be taken as recommendations by anyone. Take anything you read or hear anywhere, but especially on the World Wide Web with a very large dose of salt. The cognoscente is a skeptic