Have you ever seen those motorcycles coming at you with those headlight modulators? The pulsating headlight makes them very noticeable to other motorists. Unfortunately, these units can be rather expensive. After doing some research, I've come up with an inexpensive way of replicating these headlight modulators.

We'll need a couple of components for our project. We're going to use a Grote electronic flasher, part number 44530, to handle the headlight pulsation. We'll also be using a 30 Amp double-pole relay, Standard Motor Products part number RY48 (or NAPA PN# AR204).




Other parts include a little bit of wire (14 or 16 gage, less than a foot in length) and several insulated female spade terminals. As far as tools are concerned, you'll need a Philips screwdriver, a jeweler's flathead screwdriver (about 1/8" wide) and a pair of wire cutters/crimpers.

I've come up with two different versions of how to hook this circuit up. One way has the headlight's high beam oscillating when the headlight dimmer switch is flipped to high beam. We'll call this Option One. The other has the headlight's high beam oscillating when the headlight dimmer switch is flipped to low beam. We'll call this Option Two.

Before we begin, let's familiarize ourselves with the connections on both the relay and the flasher unit.

The Relay


The relay will have five spade terminals sticking out of it. Two of the five terminals are hooked to an electromagnetic coil inside the relay and they are marked 85 and 86. Terminal 85 is the power-in terminal and terminal 86 will be hooked to ground completing the circuit. The other three terminals (terminals 30, 87, and 87a) are for a double-pole switch. The term "double-pole switch" tells us that the switch has the possibility of sending power down one of two legs depending on its state. Our relay has two states: energized or not. The "not energized" state will have terminals 30 and 87a connected in a normally closed (nc) position, allowing power to flow across them. Terminals 30 and 87 are said to be normally open (no) in this state, i.e. no power will flow across those terminals. The "energized" state is when the coil has been powered up on terminal 85 and the relay's electromagnetic coil pulls the switch closed across terminals 30 and 87. Now terminal 87 is closed and terminal 87a is open. As soon as power is removed from terminal 85, a spring pushes the switch back to its "normal" state, closing across terminals 30 and 87a. Notice that terminal 30 is a common terminal to both states. Therefore, terminal 30 is usually referred to as the "common".

The Flasher



When you look at the electronic flasher, you will see an 'X' and an 'L' stamped on the unit. Power coming into the unit should be hooked to the 'X' terminal and the headlight high beam should be hooked to the 'L' terminal.

We will also need to adjust the flasher's rate of oscillation. You will need to carefully remove the plastic cover from the electronic flasher unit by gently prying out on the retainer clips on either side of the cover. Once the cover is removed, you will see a pot on the circuit board next to the capacitor. The pot has a small square hole in it that is adjustable. Using a small screwdriver, turn it clockwise to increase the flash rate or counterclockwise to decrease it.


I recommend doing this before building your harness as things get pretty tight afterwards. A couple of jumper wires will work to temporarily hook up the headlight and flasher unit. You'll need to hook one jumper wire to the yellow wire coming from the dimmer switch to the 'X' terminal on the flasher. Then hook another jumper wire to the 'L' terminal on the flasher unit to the yellow wire of the headlight harness. Lastly, you'll need another jumper wire hooked to the black wire of the headlight harness to ground to complete the circuit.

After securing the headlight so it doesn't fall and break, start the bike and turn on the high beam. Slowly turn the pot until the highbeam oscillates on and off at a decent rate. If you turn it too much, the high beam will not fully light and will diminish the effect. Once you have it set to where you like it, replace the cover. (WARNING: Be carefull where you grab the flasher's printed circuit board. The capacitor can give you a nasty jolt if you touch its terminials.)

Here are the steps...
1. Remove the headlight from the headlight bucket by removing the two screws from the bucket. They are located at the 4 o'clock and 8 o'clock positions.
2. Unplug the headlight from the wiring harness and set it aside for now.
3. Unplug the headlight harness from the dimmer switch wiring harness.
4. See the instructions under the flasher unit section for adjusting the flasher frequency. Adjust flasher unit.



5. Cut the headlight harness approximately in half.
6. Remove any plastic wire protector tubes from the harness and discard.
7. Determine which option you will be installing on your bike. Option One will preserve the low beam, while Option Two will preserve the high beam.
8. Go to that section to complete the install.

Option One (Preserves Low Beam)



Here's the wiring diagram I've come up with for oscillating the high beam when the headlight dimmer switch is in the 'High' position. This is how it works: power flows to the normally closed side of the relay contacts, terminal 87a, through to terminal 30. From there, power continues on to the low beam filament of the headlight. At the same time, power flows to the flasher unit, then on to the high beam filament of the headlight. The flasher unit causes the high beam filament to oscillate on and off rapidly.

To disable the headlight modulation feature, flip the headlight dimmer switch to the 'Low' position. Power then flows to the relay's coil terminal 85 energizing it (terminal 86 being grounded). At that point, the switch inside the relay closes across terminals 87 and 30. Power then flows from terminal 87 through 30 out to the low beam filament.



9. Using your wire strippers, strip the insulation off all the headlight wiring harness wire ends.
10. Twist together both the bare black wire ends and crimp on an insulated female spade terminal.
11. Plug this newly crimped female spade terminal onto the relay's terminal 86.
12. Twist together the bare green wire end coming from the headlight wiring harness's dimmer switch circuit (white plug-end) and a short piece of new wire (stripped of course) and crimp on an insulated female spade terminal.
13. Plug this newly crimped female spade terminal onto the relay's terminal 87.
14. Crimp on an insulated female spade terminal on this new wire.
15. Plug this newly crimped female spade terminal onto the relay's terminal 85.
16. Crimp on an insulated female spade terminal on the bare green wire coming from the headlight wiring harness's headlight end (black plug-end).
17. Plug this newly crimped female spade terminal onto the relay's terminal 30.
18. Twist together the bare yellow wire end coming from the headlight wiring harness's dimmer switch circuit (white plug-end) and a short piece of new wire and crimp on an insulated female spade terminal.
19. Plug this newly crimped female spade terminal onto the relay's terminal 87a.
20. Crimp on an insulated female spade terminal on this new wire.
21. Plug this newly crimped female spade terminal onto the flasher's terminal 'X'.
22. Crimp on an insulated female spade terminal on the bare yellow wire coming from the headlight wiring harness's headlight end (black plug-end).
23. Plug this newly crimped female spade terminal onto the flasher's terminal 'L'.
24. Go to step 25.

Option Two (Preserves High Beam)



On the low beam side, power flows in from the dimmer switch to the low beam filament and to the flasher unit. From the flasher, it flows threw the normally closed (terminals 87a and 30) relay on to the high beam filament. The flasher causes the high beam filament to strobe.

When the dimmer is flipped to high, the power flows into the coil of the relay (terminal 85) which pulls the contacts closed across terminals 87 and 30. This allows the power to flow from the high beam circuit threw to the high beam filament. Since there's no flasher involved, it remains constant, i.e. a normal high beam.



9. Using your wire strippers, strip the insulation off all the headlight wiring harness wire ends.
10. Twist together both the bare black wire ends and crimp on an insulated female spade terminal.
11. Plug this newly crimped female spade terminal onto the relay's terminal 86.
12. Twist together the bare yellow wire end coming from the headlight wiring harness's dimmer switch circuit (white plug-end) and a short piece of new wire (stripped of course) and crimp on an insulated female spade terminal.
13. Plug this newly crimped female spade terminal onto the relay's terminal 85.
14. Crimp on an insulated female spade terminal on this new wire.
15. Plug this newly crimped female spade terminal onto the relay's terminal 87.
16. Crimp on an insulated female spade terminal on the bare yellow wire coming from the headlight wiring harness's headlight end (black plug-end).
17. Plug this newly crimped female spade terminal onto the relay's terminal 30.
18. Twist together the bare green wire end coming from the headlight wiring harness's dimmer switch circuit (white plug-end) and the bare green wire coming from the headlight wiring harness's headlight end (black plug-end) and crimp on an insulated female spade terminal.
19. Plug this newly crimped female spade terminal onto the flasher's terminal 'X'.
20. Crimp on an insulated female spade terminal on a short piece of new wire.
21. Plug this newly crimped female spade terminal onto the flasher's terminal 'L'.
22. Crimp on an insulated female spade terminal on this new wire.
23. Plug this newly crimped female spade terminal onto the relay's terminal 87a.
24. Go to step 25.

Finishing Up
25. Carefully reposition the existing wires in the headlight bucket so that you have room for the relay and the flasher unit.
26. Plug the headlight wiring harness into the headlight dimmer switch harness (white plug-end).
27. Plug the headlight into headlight harness.
28. Reinstall the headlight, making sure not to damage the wires, connections, or components inside the headlight bucket.
29. Reinstall the headlight bezel retaining screws.
That's it! You're done.

In closing, here's a little video of the working prototype on my bike. In the video, you'll see me switching the headlight dimmer switch from 'Low' to 'High'. Note the strobing of the headlight after I've flipped the switch.


Written by Don Bangert Author of several How-To's and the blog, The Path Less Traveled

I'm not sure if anyone else has done an in depth look at relays or how they work, but I thought I'd put in my 2¢ worth on the subject. Let's start our discussion with a technical description of a relay.


What is a Relay?

"A relay is a simple electromechanical switch made up of an electromagnet and a set of contacts. Relays are found hidden in all sorts of devices. In fact, some of the first computers ever built used relays to implement Boolean gates."

An Open Relay

Relay Construction

Relays are amazingly simple devices. There are four parts in every relay:

1. Electromagnet
2. Armature that can be attracted by the electromagnet
3. Spring
4. Set of electrical contacts

The following figure shows these four parts in action:

In this figure, you can see that a relay consists of two separate and completely independent circuits. The first is at the bottom and drives the electromagnet. In this circuit, a switch is controlling power to the electromagnet. When the switch is on, the electromagnet is on, and it attracts the armature (blue). The armature is acting as a switch in the second circuit. When the electromagnet is energized, the armature completes the second circuit and the light is on. When the electromagnet is not energized, the spring pulls the armature away and the circuit is not complete. In that case, the light is dark.

When you purchase relays, you generally have control over several variables:

• The voltage and current that is needed to activate the armature
• The maximum voltage and current that can run through the armature and the armature contacts
• The number of armatures (generally one or two)
• The number of contacts for the armature (generally one or two -- the relay shown here has two, one of which is unused)
• Whether the contact (if only one contact is provided) is normally open (NO) or normally closed (NC)

Why use a relay?

In general, the point of a relay is to use a small amount of power in the electromagnet -- coming, say, from a small dashboard switch or a low-power electronic circuit -- to move an armature that is able to switch a much larger amount of power. For example, you might want the electromagnet to energize using 5 volts and 50 milliamps (250 milliwatts), while the armature can support 120V AC at 2 amps (240 watts).

Most relays work on these basic principles. However, there are a variety of configurations that you will run into and you must adjust your testing techniques for each unique situation and relay. Understanding the basics will give you the knowledge to handle the more complicated relays found not only on XJ motorcycles, but in your automobiles and home electronics. Heck, you may even get comfortable tearing one apart to "tune it up" with a point file.

I hope that everyone now understands how relays work, because we're moving on. Let's get to the testing part of this How-To...

Pictured here is a headlight relay I grabbed off my '81 Virago parts bike. I'm pretty sure it's the same relay used on the Maxim and Seca, too.

I've gone ahead and popped the cover off this relay to show you what it looks like on the inside. Just like the How Stuff Works quote above, this relay has an electromagnetic coil, an armature, a return spring and a set of contacts. This particular coil also contains a diode. A diode, put simply, allows current to flow through it in only one direction. It acts like a one-way check valve for electricity. I'll explain why this relay has one in a moment.




Looking at the picture below, we're going to be referring to the spade terminals as I have marked them since they weren't indexed by the relay's manufacturer. Note the position of the pigtail's indexing tab (yellow paint).

On my bike, power comes in on Pin 1 from the alternator. If this were for a generic lighting circuit, this could be where a toggle switch would be hooked to. From Pin 1, power flows through the coil and completes its path to ground on Pin 2. When current flows from Pin 1 to Pin 2, the electromagnetic field pulls the armature down into the coil's body. The contact lever that is hooked to the armature is then closed across Pin 3 and Pin 4. Power comes from the battery on Pin 3, and--when closed--flows to Pin 4. From Pin 4, it flows out to the headlight (or whatever we happen to be powering with this relay).

What's unique about this particular relay is the diode that ties Pin 4 back to Pin 1. The diode allows power to flow from Pin 4 to Pin 1, but not the other way. This allows power to keep the relay energized once power is allowed to flow from Pin 3 to Pin 4. As a matter of fact, you could remove power from coming in on Pin 1 and the relay's contacts would remain closed because power would flow from Pin 4 through the diode back to Pin 1. The only way to open the contacts would be to cut power to Pin 3.

To test this relay, hook an ohm meter to Pin 1 and Pin 2. You should have some continuity across these pins. Most of the time when you're testing relays there is no way of determining the what the resistance of the coil should be, so you're left with just checking whether it has continuity or not. Except for the rarest of occasions, this is adequate when troubleshooting a relay. If you have continuity through the coil, continue on. If you don't, the relay is bad and needs to be replaced.

The next test is to check whether you have continuity across the contacts. First, since this relay is normal open, let's make sure the contacts aren't welded closed. Hook an ohm meter to Pin 3 and Pin 4. The meter should show an open circuit. If it doesn't, the relay is bad and needs to be repaired or replaced.

Next, you need to energize the coil so that it pulls the contacts closed. Hook a jumper wire from the battery to Pin 1 and a grounded wire to Pin 2. The relay should make an audible clicking sound when it latches closed. With an ohm meter still hooked to Pin 3 and Pin 4, you should be reading continuity now. If it doesn't, the relay is bad and needs to be repaired or replaced.

Normally, this would conclude our troubleshooting procedure, but since this relay has an internal diode, we need to make sure it is functioning as well. As stated before, diodes allow current to flow one way but not the other. If you hook an ohm meter to Pin 1 and Pin 4, you may get continuity. If you don't, that's okay. Reverse the leads and check for continuity. If you didn't get continuity before, you should now. If you did continuity before, you shouldn’t now. If you don't get continuity either way or you get continuity both ways, the diode is bad and the relay needs to be repaired or replaced.

To repair the relay, you can sometimes file the contacts with a point file. This will extend the life of the relay for awhile, but you really should start looking for a new replacement. If the diode is bad, you can remove the old one and solder in a new one in its place. If the coil is bad, the relay is pretty much junk. Toss it and find a new one.

As you check relays, you'll find most manufacturers will print the relay's diagram and pin locations on the body of the relay. However, sometimes they don't and you're forced to either open them up to see how they work or just replace them with new ones. I generally opt for option 1. Besides, if I break one while trying to pry the cover off of it, I've still got the other option to fall back on. Very Happy

That brings us to the end of this How-To. I hope the information I've provided here is useful and helps you diagnose your relay problems.

Written by Don Bangert Author of several How-To's and the blog, The Path Less Traveled

You see it every time you climb on your bike. It sits there providing you with a mountain of information for your riding pleasure. It does its job without complaint. But every once in awhile, something goes wrong and you're forced to open her up.

Well, that's the case for this latest installment in my "How-To" series. When I bought my bike, I noticed that the tachometer light wasn't working. It was mid April heading into summer. I was a new rider and had no plans on riding at night, so I didn't bother fixing it.

Well, times have changed. Here it is the beginning of October and I'm fighting tooth and nail for every riding day I can get. I've embraced—with open arms—the idea of riding at night. But, that burned out tachometer light has got to be fixed. I've just got to know what's going on in the engine room.

Enough of that. Let's get started with our project.

Here are the steps...
1. Remove tachometer cable (if so equipped).
2. Remove speedometer cable.




3. Remove instrument cluster mounting bolts.




4. Remove headlight from headlight bucket.
5. Unplug and fish through the wiring harnesses for the speedometer lights, the tachometer lights, (the tachometer head, if so equipped), and idiot light tree.


6. Remove the instrument cluster.


7. Remove the screws from the rear of the instrument cluster.


8. Remove the chrome housing.
9. Remove and replace the light bulbs.


10. Perform any other work that needs to be done (cleaning, lubing, etc.)




11. Reinstallation is the reverse process.

That's about it. This one's pretty easy to take care of.

Bonus Tip: if you scroll back up and look at the instrument cluster you'll see a small digital clock affixed to the tachometer. That's held there by a piece of Velcro. This allows me to remove it when I wash the bike or find myself in a heavy down pour. Underneath the head cover (that plastic piece surrounding the ignition switch) you'll find another piece of Velcro. I can stick the clock there until the wet condition passes.

(Written by Don Bangert Author of several How-To's and the blog, The Path Less Traveled

This is a How-To on replacing the oe fuse box with a more reliable aftermarket ATO-style fuse box. Before we get started, we'll need to collect a few pieces. We'll need a fuse box. I picked mine up from the CARQUEST store where I work. It's a reboxed Littelfuse brand going by the part number 350417BP

In addition, you'll need a couple of mounting screws (8x1"), electrical tape, a couple zip-ties, a box of female insulated spade terminals, and fuses (ATO10 amp x 3 & ATO20 amp x 1).

Tools? Phillips Screwdriver and Wire Cutters/Crimpers/Strippers.

Okay... Ready? Here we go. Let's meet the patient:


My wife's '82 XJ650J Maxim.

Here are the steps...
1. Remove Seat.
2. Remove Right-Hand Access Cover exposing battery.
3. Disconnect battery.
4. Unscrew old fuse block.


5. Note fuse sizes and wire colors.


6. Pry open metal wire retainer ring at the base of oe fuse box.


7. Place zip-ties around left- and right-hand wire bundles and unwrap tape.
8. Cut wires at crimp joints.
9. Take new fuse box and position it for mounting, making sure all the wires will reach their respective terminals.
10. Strip wires and install female insulated spade terminals.


11. Tape wires bundles and attach terminals to fuse box.
12. Using the two #8x1" screws, mount the fuse box.


13. Install fuses and dust cap.


14. Reconnect the battery.
15. Install side cover and seat.

That's it. You're done!

(Editor's Note) It occurs to me that if you have a tool caddy you'll want to make sure you allow room for it


Notice how I've bent the spades a little to make the connections a little more convenient. I still need to label the fuses. From left to right, they're 10A IGNITION, 10A SIGNAL, 10A HEAD L., and 20A MAIN.

(Written by Don Bangert Author of several How-To's and the blog, The Path Less Traveled.)

Start with the bike on the center stand with side stand up and the transmission in neutral. You will also want the ignition switch turned to on and the kill switch turned to on. The numbers in the picture coincide with the steps listed below.

1. Test the voltage at the battery. It should read at least 12.5 volts. Charge and retest as needed.

2. Using an old screwdriver, short across the two large terminals at the starter solenoid. This will bypass the solenoid and allow the starter to crank the engine. If the starter doesn't crank, perform a continuity test between the negative battery terminal and the engine case. If you read no resistance (or almost no resistance), repair or replace the starter. Otherwise, repair or replace the ground cables and retest.

3. Locate the pigtail from the starter solenoid and unplug it. Using a jumper lead, hook the Red/White wire from the solenoid to the battery's positive terminal. Using another jumper lead, hook one end to the solenoid's Blue/White wire. Momentarily touch the other end of this lead to the battery's negative terminal. If the solenoid is functioning properly, the solenoid should click and the starter should begin cranking the engine. Repeat this step several times to ensure the integrity of the solenoid. If nothing happens, repair or replace the starter solenoid

4. If the solenoid checks out, hook your continuity tester between the battery's ground terminal and the Blue/White wire coming from the bike's wiring harness for the starter solenoid (solenoid pigtail unplugged). It should read an open state while the starter button is not pressed. When you push in the starter button, the tester should then read a closed state. If there's no change, inspect, clean, or replace the starter button switch and its ground and retest.

5. Using your voltmeter, hook its ground wire to the battery's negative terminal and its positive wire to the Red/White wire coming from the bike's wiring harness for the starter solenoid (solenoid pigtail unplugged). The meter should read 12 volts (approx.) if the bike is in neutral, and/or the clutch lever is squeezed and side stand is up with the key on and the kill switch on. If not, inspect the wire coming from the starter circuit cut-off relay for any breaks or chaffing. If the wire looks good, go to the next step.

6. Remove the left-hand side cover to gain access to the starter circuit cut-off relay. Using your voltmeter, hook its ground wire to the battery's negative terminal and its positive wire to the Red/White wire coming from the kill switch (starter circuit cut-off relay pigtail unplugged). The meter should read 12 volts (approx.) if the ignition switch is on and the kill switch is on. If not, you will need to inspect, clean or replace the 20A Main fuse, the ignition switch, the kill switch, or the wiring between them. If you measure 12 volts (approx.), go to the next step.

7. Hook your continuity tester between the battery's ground terminal and the Sky Blue wire coming from the bike's wiring harness for the starter circuit cut-off relay (relay pigtail unplugged). It should read an open state while the transmission is in gear. When you shift into neutral, the tester should then read a closed state. If there's no change, inspect, clean, or replace the neutral switch and its ground and retest. If it checks out, proceed to the next step.

8. Hook your continuity tester between the battery's ground terminal and the Black/Yellow wire coming from the bike's wiring harness for the starter circuit cut-off relay (relay pigtail unplugged). It should read an open state while the clutch lever is released and/or the side stand is down. When you squeeze the clutch lever and the side stand is up, the tester should then read a closed state. If there's no change, inspect, clean, or replace the clutch and side stand switches and their grounds and retest. If they check out, proceed to the next step. (Note: some models may not have a side stand switch.)

9. If all previous tests have passed, replace the starter circuit cut-off relay and try to start the bike again. If it still doesn't start, have your bike exorcised of demons by a Catholic priest and retest as there's really nothing else that would keep your bike from cranking over.

(Written by Don Bangert Author of several How-To's and the blog, The Path Less Traveled.)