Getting LED tail light signals to flash???

[jeeptman]

I just installed LED tail lights in my '86 CJ-7. All is great except they won't flash. I read the thread below and tried replacing my flasher with an electronic HD unit to no avail. For my next trick, I am going to install the resistors mentioned but being electrically inept, am not sure exactly how they are to be wired in. Anyone out there have a diagram or at least be able to explain how these resistors are to be installed. Any help would be much appreciated.

http://www.pirate4x4.com/forum/showthread.php?s=&threadid=40524&highlight=LEDs

Thanks,
Trevor

[KC_JoNeS]

The idea behind adding a resistor is this....

a standard LED (or light emitting diode) only drops 0.7 volts. This is not enough drop to generate enough current for the relay to recognize. So a resistor is placed in series with the LED tied to ground. With the resistor tied to ground, the signal pin is normally low and when the signal line goes high, the LED goes on.

[jeeptman]

There are three wires which connect to the light. One for the Tail light pwr, one for brake/turn signal pwr and the other for gnd. Which one of these am I tying into? Do I go from the turn signal power lead on one end of the resistor then tie the other end of the resistor to gnd? Or am I to splice it into the gnd wire? Sorry, it takes a little for this stuff to sink in... :confused:

[JeepinDoug]

I did this for my front grill lights, wired them into the side marker lights. It's the same configuration, diode stripe goes torwards the light. Radio Shack p/n 276-1653.

[Phatj33pyj]

I swapped the hazard relay and the blinker relay and they both work now. The hazards blink slower. But the turn signals work great.

[jeeptman]

That's the wierd thing about mine. There was only one flasher relay and it was plugged into the hazzard socket. I looked at the T/S socket and there weren't even any metal tabs in it to accept a relay. So, it seems that mine was set up to run both the t/s and the haz off the same relay. Oh, and the hazards flash just fine.

[apeters89]

Originally posted by jeeptman
That's the wierd thing about mine. There was only one flasher relay and it was plugged into the hazzard socket. I looked at the T/S socket and there weren't even any metal tabs in it to accept a relay. So, it seems that mine was set up to run both the t/s and the haz off the same relay. Oh, and the hazards flash just fine.

The hazards flash fine because it is flashing all four lights at one time, the combined draw is enough to throw the flasher unit... only 2 bulbs at once is not enough draw without a resistor of some kind... but I thought it had to be wired in parallel, not series to make it work right.

[TATER]

If you take 2 resistors @ 8 ohms each, wired in series would be 16 ohms. Take same resistors, wired in parallel would be 4 ohms.


So, a resistor wired in parallel may not provide enough resistance.

[NOODLES]

electronic flasher, or you can go ahead and buy a trailer harness, it is a expensive way to add diodes, but is easy to put on by anybody.