Kriss Motorcycle Products

Technical Support - Brake Light Flasher
Built on questions from users

Installation instructions must be followed exactly and all steps completed prior to applying power or the unit will be damaged. Connecting the unit backwards will damage the unit.

Problem

We are using this particular example to reveal what takes place more times than not.
We are providing this exchange so you can see the results of an incorrect installation. The customer bought a closeout model headlight modulator and returned it because he said it didn't work. We didn't find anything wrong and agreed to give him credit toward one of the newer models. He insisted that he knew what he was doing and did everything correctly.
Customer: I installed the replacement modulator tonight and it doesn't work either. It actually blows the motorcycle fuse when switched On. Prior to installing the unit I took great pains to insure it was connected properly and used a multimeter to confirm each wire of my circuit plug. I also tried it on my bench power supply and it makes the supply go into overload protection. I'm an electrical engineer so I understand electronics. Can I send this thing back for a refund? As much as I want it to work, I'm tired of messing with it.
Us: Sorry but that won't be possible. I can tell you without any doubt that you've connected the unit backwards. If it's blowing the fuse or putting a power supply in overload then you've blown the suppression diode in the circuit which prevents total destruction.
Note: We sent him a photo of the component in question and suggested he open the case and check the diode with an ohmmeter.
Customer: Thanks for the picture and explanation. I took the box apart and checked the diode. Not only was it shorted, but the top was blown off. I replaced the diode and hooked it up to my bench power supply. It worked fine. Before I hook it to the bike I'm going to go through the wiring again and double check things.

Be sure to check your battery, especially after all the testing on an installation.

Question: Programming doesn't seem to work. I touched the wire and counted the flashes but unit didn't change program when the unit was turned back on.
Answer: After counting the programming flashes and disconnecting the program wire the power must be left on the unit for about five seconds before turning the power off and back on. This is because the programming is not completed for several seconds after the program wire is removed from +12 volts. Also, we've found that some people wait until after the desired number of program flashes are completed. The wire must be disconnected when the last flash comes on and disconnected rather than after the light goes out. The result is the program is now in the next program instead of the desired program.

Question: After installation the unit didn't flash correctly when the brakes were applied. Sent the unit in for testing which confirmed nothing wrong. After installing again the same problem resulted.
Answer: It turned out that the battery was run down during installation and testing and the engine wasn't started or the battery charged. If the battery voltage is below 12 volts (normal operating voltage is 13.8- 14.2) the brake sensing circuit voltage will be low and the unit won't function properly.

Question: How do I bench test the Brake Light Flasher Unit?
Answer: Connect the Red output wire to a 12 volt bulb (even a test light is OK). Attach the Green ground wire to battery negative first and then Yellow/Red to battery positive. The light should run through a flash sequence. From the factory it's programmed for about four flashes and the it will stop and remain steady on. Remove the positive wire (yellow/red) from the battery and the light will go out. Each time this wire is connected to the battery the flash sequence will be activated. If the unit passes this test the unit is functioning properly.

Always use a test light when checking circuits.