(Revised June 6, 2011)
The following is a compilation of the information in a thread that I started at zukikrawlers.com called Simple LED Turn Signal Mod
The Basics
LED automotive lighting fixtures are rugged, energy efficient and all around cool!
But they have their little quirks, too.
One of those "quirks" is how they work with a typical turn signal flasher unit.
The typical flasher unit found in a Suzuki Samurai (and many other vehicles manufactured without OEM LED turn signal lights) depends on the
typical current load presented by a regular automotive light bulb that it controls in order for it to work properly. Because LED lamps draw far less
current than an equivalent incadescant bulb, the flasher "thinks" that a new LED lamp installed in the turn signal circuit is a bad regular
bulb and "fast-flashes" when activated. The "fast-flashing" lets the driver know that a bulb has burnt out - except in this case it's only
the working replacement LED "acting" like a burnt-out bulb!
How do we fix this?
The correct way is to buy a flasher unit designed to work with LED lamps.
Unfortunately, if you walk into an auto parts store and ask for one, the Counter Gal/Guy will look at you and say "Whut?" The next words
out of his/her mouth will be "what year and model vehicle do you have" then proceed to tell you that the flasher unit is OEM part # XYZ - which is
NOT a flasher unit designed to work with LED lamps!
Fortunately, this article has the answer. It is called the EP34 electronic flasher manufactured by Tridon.
These JSO-spec flashers - as opposed to ISO-spec, which are used in US vehicles - are "plug-and-play" flasher units that will work on your Samurai.
Here is a pictorial that shows the difference between the JSO and ISO flasher pinouts
The EP34 is easier to find and will work IF there is at least one regular bulb in the turn signal circuit.
[Edit: It has been pointed out that there is an error in the following sentence. It now reads correctly.]
You can modify the EP34 to work with "LEDs all around" by opening the case and disconnecting pin seven of the integrated circuit by either lifting it as pictured below
or cutting the pin with a very small pair of diagonal pliers :
This mod disables the "fast flash" function of the EP-34.
Note:
Although it has been suggested that the EP-35 unit does not need to be modified, it is an ISO-type flasher and cannot be used in your Samurai
without reversing the 12VDC and Ground wiring in the Relay socket. As of this writing (June 5, 2011), there may be a new version of the EP-34 that
does not need modding.
Other Important Stuff
Many Samurai owners have installed a trailer light conversion unit so that he/she can use a "Combination" or three-wire Tail light.
The trailer conversion unit combines the stop and turn signal circuit so that only one bulb is needed instead of a separate bulb for
brake and turn. Unfortunately, the trailer conversion unit causes the emergency flashers not to work when LED lamps are installed! This is because turn signal flasher unit
also drives the emergency flashers - which is actually both turn signal circuits blinking together. If your truck is wired this way,
and you want to install LED turn signals, you need to remove the Trailer converter and add separate LED turn signal lamps to your rear bumper!
"Resist" the temptation of using a resistor to fix the fast-flash problem!
You may have read somewhere, saw a resistor fast-flash kit on eBay or was told by a guy at the local offroad store that you can simply wire a resistor in parallel to your turn
signal circuits. This not a good idea! There are documented cases where a resitor was installed improperly or the wrong type/value of
resistor was installed resulting in a catastophic vehicle fire! If that wan't bad enough, fixing the problem with a resistor reduces the
efficiency of the LED flasher circuit. What's the point in that???
Play it smart and use a flasher unit designed for LED turn signal lamps.
