Electronic voltage regulators and rectifiers have no internal moving parts and must be replaced if found to be bad. the main symptoms of a bad voltage regulator are:

1. The battery will discharge.

2. The battery will be over-charged.

3. The light in the electrical system will start to burn out quicker than they should.

In most normal cases, inspecting a voltage regulator, just simply run the engine at the recommended engine speed and check the DC current at the battery. If it is overcharging, it's the regulator that has gone bad and should be replaced. If it is undercharging, and all the other charging components are working right, then it is the regulator that is probally bad.

Rectifiers are somewhat easy to test. Just use an ohm-meter, and connect the ohmmeter to the ends of each of the diodes and check the resistance in both directions. The resistance should be low in one direction and very high in the opposite direction. The exact specs are usually given in most shop manuals. A general guideline for testing most diodes is to have 5 - 40 ohms of resistance in the forward bias direction (where the current is allowed to flow), and infinite resistance in the reverse bias direction (where the current isn't allowed to flow).

Testing the rectifier involves attaching the black probe of the meter to the ground side of the rectifier and the red probe of the meter to each of the three contacts. Record the numbers. Then swap around the meter leads (red and black are swapped) and take the readings again. You have thus measured the ground side of the rectifier.

Testing the battery side of the rectifier involves attaching the meter probes to the battery side of the rectifier and testing the doides in the same way as just described. Once that is done, you should have about twelve readings that are the forward and reverse bias measurements for each of the doides.

Always remember, if you are buying a used electrical item. There is a good chance it could be why the bike stopped running in the first place and was taken apart and sold for parts, since most electrical problems are very hard to find, they usually go un-repaired and create frustration in the bike owner leaving them with a sad feeling and just simply wanting their money back out of the bike. If it is an item that has been tested, than all is good!! Just make sure the specs are what they are supposed to be. If it is a new item, then there shouldn't be any reason to test. Just make sure to test your old parts so you will know that is what the problem actually is in the first place.

Most multi-meters are relatively in-expensive, and can be found at almost any parts store, or your local hardware store. A good multi-meter will be able to test almost anything in your home, garage, car, motorcycle, ATV, etc., and is one of the best items you can add to ANY tool collection!!