Kriss Motorcycle Products

Technical Support - Trailer/Accessory Isolator
>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: How do I bench test the Isolator Unit?
Answer: Attach the green ground wire to battery negative first and then yellow to battery positive.
Touching the brown sense wire to +12 volts should cause the #1 screw terminal to turn On.
Touching the green/red sense wire to +12 volts should cause the #2 screw terminal to turn On.
Touching the blue sense wire to +12 volts should cause the #3 screw terminal to turn On.
Touching the orange sense wire to +12 volts should cause the #4 screw terminal to turn On.

trailer isolator #1 terminal is on the left.

Always use a test light when checking circuits.