Modifying flasher for LED use

LED taillights are efficient, long lasting, light up faster (I'm told 200 milli-seconds faster than incandescent, 1/5 of a second faster... about 20 feet at 60mph).  Because of the fast light up time, they can also make you more noticeable in traffic.

There is a side effect, though.  The LEDs are so efficient that they make your turn signal hyper flash to indicate that a bulb is out.

Some people install load resistors to get the flasher to work right, but they defeat the purpose of installing efficient lights.  LED flashers are available for $20-30.

But you can modify your current flasher for free.  I'll show you how I did mine for a GM pickup.  Jeeps are very similar.




Open the case by gently prying the side tabs and sliding the cover off.



The above picture is actually the modified flasher.  In the picture, directly above the chip in a diagonal trace.  I cut/scratched through the trace.  This is the part that monitors the load.  Now it will just flash at one rate.  This will also work with the additional load of a trailer BTY.

Steve

Slick!

When I modified the tail light format on Boomer the flashers were obviously all screwed up. VERY fast flash rate. I ended up replacing the thermal flasher controller (which most vehicles up until the last 5 or 6 years come with) with an electronic flasher. The electronic flasher doesn't use a bimetal element and current to control flash rate....just an electronic circuit. The old school flashers get messed up due to the electrical current increasing or decreasing as a result of different bulbs. That current is used to change the temperature within a small piece of metal which changes shape with temperature. As it heats up due to connecting a circuit, it warps and breaks the connection. This allows the bimetal to cool which then causes the warp to decrease which then makes the switch again. The clicking you hear from a blinker is that bimetal warming and cooling over and over.

Electronic flashers are pretty cheap (under $10) and are available as replacements for most vehicles at your local auto parts store.

SG