Auto light systems

[Pappy]

The wiring harness for the trike is set up with the tail lights on the fenders to function as tail lights and turn signals. A load equalizer is used to supply power to 2 small LED lights below the bumper that are tail/brake lights. I want to make the fender mounted lights function as tail/brake/signal lights.

The original Harley lights, like most bikes, use separate brake/turn signals. This would be similar to the set up on cars that have amber rear signals, except that the Harley only had one tail/brake light. To run trailer lights with these cars, a converter box is wired in that combines the brake and turn signal functions to operate on the same 1157 bulbs.

My thought is to get a converter box and wire it into the original rear harness. The LED load equalizer would be split off between the connection and the converter to power the 2 LED lights as they are set up now. After the converter I would have 4 wires to power the fender mounted lights that would be the same as a trailer harness.

White Ground
Brown Tail light
Yellow Left Turn/Brake
Green Right Turn/Brake

Any one have the expertise to tell me if this will work or not? If not, is there a way to make it work?

[cabinetman]

It sounds like it would work. I would do a temp hook up as a test.

.

[LCHIEN]

I'm an electrical engineer, but not real familair with auto electricals.
I had to look up LED load equalizer. Basically, some turn signals (these are old school, that use the current and electro-mechanical sensing) use the current load of the lights to indicate burned out lights. They blink at twice the normal 1-second interval if only one bulb, not two are connected and drawing current.

So LEDs draw so much less current than an incandesant 1157. So they add a resistor in parallel to draw more current so when the LEDs are used with the blinkers then it will blink at the right rate. They probably charge a pretty penny for this.

If they build load equalizer boxes, maybe you should check and see if they have blinker modules that don't have this missing bulb/blink faster feature... it seems like it should exist and keep you from 1) wasting power in a load equalizer runs real hot and may burn up and 2) simplify things with a single blinker module in the original location and socket and no load equalizer

In this forum thread some guy suggests replacing the turn signal module with a electronic one as I suggested so apparently they exist.
http://www.hdforums.com/forum/tourin...-required.html

Add'l comments: LE not required for tail/brake lights, only turn signals?
Are you going all LEDs (front and rear) or just rear?

[LCHIEN]

Did you look at something like this?
http://www.customdynamics.com/trick_flasher.htm

[mpc]

I don't know what "flasher" unit H-D uses and how it compares to what some cars used back in the 70s-80s-90s when the amperage draw of incandescent bulbs was a critical part of the operation (similar to what Loring posted). The "EL-10" is a plug-in replacement for certain older mechanical flasher units to allow LED operation directly and was available at chain-style auto parts stores.

What Loring posted describes many of the turn signal flasher units used in cars; another common style kinda worked the opposite way: they were self-resetting thermal circuit breakers. Current flow through the turn signal bulbs heated the flasher; at a certain point the heat caused the unit to trip, cutting power to the bulbs. After it cooled, it'd self-reset and the bulbs came back on. If a front or rear bulb was out (the bulbs were wired in parallel, not series), then the current flow was cut in half and the unit didn't heat up enough to thermally trip - the working turn signal bulb and your dash/instrument panel light would just stay ON constantly to indicate a burned-out bulb problem. Opposite what the system Loring described: instead of blinking faster, this system stops blinking completely when a bulb burns out (or is replaced by a LED)!

Cars with this style flasher unit generally had a second one dedicated to the HAZARD function. This second one a) had a different heater unit since it was powering twice as many turn signal bulbs so it was a slower heater to compensate and b) was hooked into the vehicle's always-ON battery leads; the normal turn signals typically hooked into the battery/power feed circuits downstream of the ignition switch ON position. Does the H-D have a hazard function? If so, it may also need tweaking to handle LEDs.

The EL-10 is a simple on/off oscillating timer that isn't based on the current flow (amps) of whatever it's controlling: bulbs or LEDs. So it can replace both the regular turn signal flasher unit and the hazard flasher unit. Assuming they have compatible pin-outs.

mpc

[Pappy]

I added a Hopkins #48845 converter to the original Harley rear light harness with limited success. I had tail/turn/brake light function but with some cross over on the turn mode. (Faint flashing of the non selected signal). Flashers would only work with one of the brakes engaged. The unit is the lowest in their line of converters. Made a call to the Hopkins help line and was told that the next level up (#48895) would work in this application and would eliminate the need for a separate load equalizer for the LED lights.

Before I buy a new converter I have a couple of other ideas I want to try using the Motor Trike harness. I am going to add the converter to the harness before the LED load equalizer. If that doesn't work, I will try it after the equalizer as I described in my first post.

Loring, the Custom Dynamics unit you linked is for metric bikes but they have units designed for the Harleys. I will have to call them to see if any of their products will work in my application.

[JimD]

Don,

What you're describing is a lot like wiring a car for a trailer. I've done the trailer wiring a few times now. Each time I've done this it seems like the car got "smarter" and wiring it became more challenging. The Harley we had seemed more like my current cars - complicated. I think a little "smarter" converter is a reasonable next step. I hope it works.

Jim

[Pappy]

What you're describing is a lot like wiring a car for a trailer.
Jim

Pretty much what I am doing.

I took the basic converter back to Autozone and, even though I had stripped the brake and turn wires to hook it up, they exchanged it for the better unit so it only cost another $10 to upgrade. Going to take a couple of hours to solder and shrink wrap all the wires back together make the harness fit the way I want it to.

[Pappy]

Success!

After several attempts with different light converters, I got everything working. With a converter that had a built in LED load equalizer I could get the light working, but blew the 15 A fuse on the bike.

The solution was to use a power converter that draws power from the battery. It doesn't draw any power unless the ignition switch is on.

I shot a video of the lights but could get it to download.

[cabinetman]

Success!

After several attempts with different light converters, I got everything working. With a converter that had a built in LED load equalizer I could get the light working, but blew the 15 A fuse on the bike.

The solution was to use a power converter that draws power from the battery. It doesn't draw any power unless the ignition switch is on.

I shot a video of the lights but could get it to download.

Congrats. I feel that way every time I get my trailer lights to work.

.