Kriss Motorcycle Products

Installation Support - Harley-Davidson Single H4 bulb Headlight Modulator
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.

If you need installation support (please see note*)

1. Contact Engineering support

2. The link is used for ordering wiring diagrams.

Note
Free technical support is offered for one (1) year after purchase for Platinum products. We always try to help
but detailed support and troubleshooting isn't available after 10 or 15 years or when installing on another bike.
Electronics product support is for our customers who've already purchased products directly from Kriss.
Free support does not cover wiring diagrams which are covered under the "Lifetime Wiring Diagrams" program.

The engineering dept. doesn't handle pre-sales questions regarding which item to select for your motorcycle or operation.

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 multi meter 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.
A customer called explaining he was sure everything was connected properly but the unit he was installing would not work properly. We suggested he remove the unit and perform a bench test which resulted in proper operation. He was really puzzled. We suggested that the battery should be checked as these small batteries can be depleted quickly when the electrical system and all the lights are on while installing an electrical device. He called later advising that he'd charged the battery and now everything works as advertised.

WARNING ABOUT JUMP STARTING
A customer recently had a dead battery after leaving the key on overnight and tried to start the motorcycle with a battery charger, rather than jumping from a battery, which caused a high voltage spike that damaged one of our brake light devices. Always charge the battery for a couple of hours and then disconnect the charger before cranking the engine which creates a very high load demand. It's best to jump with a battery that's not being charged at the time, either by portable charger or a running automobile engine. Voltage spikes over 18 volts can damage radios, GPS units and other electronics. Our units contain over voltage protection up to 18 volts without damage. Above that our protection component will short to protect the circuit board.

Question 1: After installation the unit would not modulate. The bike was still in the garage under florescent lighting.
Answer: The IR detector is not triggered by florescent light. It requires either sufficient sunlight or an incandescent bulb.

Question 2: After installation the unit would not modulate. A flashlight was used to trigger the IR detector.
Answer: The light was not left on the detector long enough. There is a one second delay in the programming.

Question 3: After installation the unit would not modulate. Customer said the light detector had been placed inside of the fairing as a good hiding place so it couldn't be seen.
Answer: Move the light detector to a position so it will be exposed to sunlight.

Question 4: After installation the unit would not modulate the headlight. The mechanic had the bike in the shop and the headlight set to low beam.
Answer: Select high beam and shine a flashlight on the light detector. This solved the problem.

Question 5: Had mechanic install modulator but decided I wanted the low beam to modulate so the mechanic swapped the wires. After that the unit would not modulate.
Answer: Reversing the wiring and connecting other than designed will damage the unit.

Question 6: Customer was not able to install unit because he didn't understand electrical wiring.
Answer: Installation of this unit is by inserting the plug of the unit onto the bulb and plugging the wires into the original plug. If the installer is not qualified to perform this task it's recommended that he should seek assistance.

Question 7: After installation the unit would not modulate correctly or stop modulating. The flash rate was very slow, about 1.5 seconds on and 1.5 seconds off. The unit was returned for inspection and found to function properly.
Answer: The customer incorrectly attached the programming wire to a +12 volt source. The unit was in constant programming mode.

Question 8: What is the Red wire for that's attached to the modulator and where is it connected.
Answer: This is the programming wire. It's connected only if you want to change the factory default setting for the light detector delay time. If no change is desired then ignore the wire. If you want to make a change then follow the procedures shown in the programming table on the instruction sheet.

Question 9: Does the headlight modulator work only during the daytime and not at night?
Answer: The headlight will modulate only during the daytime when the high beam is selected. The bulb doesn't modulate at night under normal circumstances.

Question 10: I have a 2011 HD Tri Glide. 7 inch single headlight. Sensor installed by HD tech below head light. Just below the running lights. I have had these on ALL of my 9 bikes. Love the product. Problem: Will not stop modulating. In my completely dark, no windows in shop at 9 pm... Still modulates. I even placed black electrical tape over the sensor, still modulates on high beam.
Follow up : Taking into consideration the impeccable track record you all have for making it right the first time, I went to my trike and reexamined the electric tape that I had applied to the sensor. Ah ha !!! Not totally occlusive. When I made the tape completely occlude the sensor, the headlight stopped modulating. Positioning is important. I did finally find a suitable placement for the sensor. Finally the the product behaves as expected. I will advise the Harley technician what caused the interminable modulation.
Answer: The sensor was placed too close to the lights so it was picking up light and thus the modulator was doing what it's supposed to do, modulate when the sensor thinks it's daylight.

This problem is guaranteed to happen when people don't follow the instructions.
Question11: I installed via the instructions and ran the programming to a 12 volt source. It started blinking slowly but never stopped, therefore I just disconnected the 12 volt source and shut the bike off. The issue is it only works on low-beam and my high/low beam indicator on the bike just stays lit when I switch it to low.
Answer: As stated in the instructions the programming wire is not supposed to be connected except during programming. If it's connected then it will continually flash slowly because it's in the programming mode. The flash during programming works only on the modulated high beam so if the low is what's flashing then this instantly confirms you reversed the connections to the Harley factory plug. On the issue about the high beam indicator, it would light up when low is selected if the connections are reversed. Sounds like you didn't get the three wires inserted in the plug in the proper order.
Question: He then reversed the high and low and blew a fuse. The customer insisted his connections were correct.
Answer: He then sent us pictures to show he'd correctly made the connections. These revealed he'd reversed the ground and low beam. When we earlier advised of the reverse connection he swapped the low and high wires but again failed to look at the instructions and now had the high beam connected directly to ground. "SHORT circuit time".

This problem appears to be the old classic one of "when all else fails read the instructions. If the installer inserts the wires into the Harley factory plug according to where it appears they terminate then a mistake is guaranteed. There is a cover on the back of the plug so it's not apparent that the wires change direction inside of the plug. Installation MUST be according to the identified positions on the picture of the plug in our instructions.

Here's the mistake. The yellow wire DOES NOT supply the terminal on the right side (3 o'clock position. Those that don't take the time to read the instructions or decide that we must have made a mistake in the instructions or maybe that we don't know what we're talking about are guaranteed to find the modulator doesn't work properly and is often damaged. If you don't like where the wires terminate call Harley-Davidson and complain. It doesn't help complaining to us.

Question 12: Called saying the modulator worked but the high beam indicator was on all the time even when the low beam was on. (same problem as above)
Follow up : During discussion and inspection he discovered the modulator low beam and ground wires were reversed when inserted into the factory plug. He apparently didn't hold the plug oriented as shown in the instructions and confused where the wires are inserted. (see above)
Answer: After reversing the two wires everything worked normal.
Our explanation as to what was going on while the wires were in reverse order is as follows:
a. When selecting high beam the indicator is turned on and the modulator is powered with +12 volts which puts power to the

high beam filament. Current will take the path of least resistance so in this case it found a path to ground through the low

beam filament which was connected to ground. The light was on but would have been at a slightly reduced intensity.
b. When selecting low beam the +12 volts was applied to the ground side of both filaments since the wires were reversed.

The low beam filament found its ground through what would normally be the positive side (remember that the wires were

reversed) so the bulb lit.
c. The positive voltage applied to the ground side of the high beam bulb (remember ground was reversed) provided a feed back

(backwards) through the high beam modulation circuit to the high beam switch. Even though the high beam switch was open

the reverse current flow supplied power to the indicator light. The light has its own ground so any applied voltage will turn on

the light.

This is the correct order of the wires.

TIPS -

Question: How do I bench test the modulator Unit?
Answer: Connect the White/Black output wire (with attached 3 position plug this will be the slot on the left when looking at the insertion side) to a 12 volt test bulb (even a test light is OK). Attach the Black ground wire to battery negative first and then the White/Black input (spaded) lead to the positive post. The input wires are always in the larger bundle of wires. The test light should illuminate. Shine a flashlight on the light detector to confirm the light modulates. Remember that there is usually a one second delay before modulating and a four second delay after removing the light from the detector lens. The Yellow wire is the low beam and doesn't need to be connected.

Always use a test light when checking circuits.