A bad microphone will not produce any signal when you talk into it. NOTE: Our microphones don't use battery power because the Asian motorcycle manufacturers don't have power on their mic lines, meaning they intend to use dynamic microphones or externally powered condenser or electret-condenser mics (used in computer mics, cell phones, etc...). The dynamic mics are like a tiny speaker and produce a signal strong enough to be amplified without any pre-amplification.
If you can't hear your microphone, the first place to look is at the various settings on your bike. Any of these can fool us if we're not careful. The intecom should be on, and the volume set about mid-range. Make sure the handlebar or other mute button isn't on. Also, make sure the microphone/music mute setting is disabled (most GoldWings have this setting, for example) This can confuse your troubleshooting.
Once you're sure the intercom is on and working and not muted or disabled in any way, speak into the mic at a close distance and you should hear yourself in the helmet speakers. If not, check the microphone with a volt-ohm meter amking SURE it's not connected to the bike, because you will be reading the input impedance of the intercom in parallel with the microphone giving you a false reading. The mic by itself should read about 500-600 Ohms on an Ohmmeter, and this test will not damage it. If there's no continuity directly at the mic, it's probably bad. On a good mic, if you listen closely when you test it, it will make a small noise when you apply the test leads. This is normal, and proves you're working with a real dynamic mic. If it does test ok on the mic solder points, then you can follow the leads out to the helmet connector.
If the mic tests ok, then go out to the helmet connector and check across the 9:00 and 10:30 position holes with the center hole at 12:00 position looking into the helmet connector. You should read the same resistance as you saw on the mic itself, if not, then the helmet connector is bad.
If the helmet connector and the mic are ok, check the coiled cable. The pins on the coiled cable to check are the 1:30 and 3:00 pins looking onto the end of the male coiled cable with the center pin at 12:00 position...just the reverse of the helmet connector. Plug in the coiled cable to the helmet connector and check the 1:30 and 3:00 pins and if you don't see the mic there as 500-600 Ohms on the lower part of the coiled cable that plugs into the bike, then you've isolated the problem to the coiled cable if the mic and helmet connector are ok..
Finally, if you DO see the mic resistance down on the lower cord's pins, then your helmet headset is probably ok and your bike is having troubles or some setting is interfereing with the mic operation.
Don't apply batter power to it under any circumstances. We don't warranty mics that have burned or melted voice coils as this is an indicator of being connected to a non-supported intercom system such as Harley, J&M or others that use powered mics.