Mopar Action On-line – Tech Questions


Tech Question

mark franklin, bowie, MD, 1970 Dodge Challenger 340

Based on your 12-05 article I decided to install LEDtronicsplug in units for all the 1157 bulbs (F&R) in my car. Also installed an EL12flasher. Now the turn signals take a couple seconds to activate, almost likethey have to warm up. However, the four ways work like a charm. Any ideaswhy this is happening? Turn signal switch? Appreciate any thoughts you haveon the matter. Thank You.

Mark, because you have LEDs front AND rear, there’s now almost zero load onthe flasher. Although we didn’t have room to mention it in the article,that’s a reason that we didn’t recommend doing the fronts also.

The stock 32cp “bright” filaments drew about 2.1 amps each, so a stockerwith one lamp at each end of the car placed a 4.2 A. load on the flasher,and a three-lamp car, 6.3 amps. The LEDs cut this down to a few hundredmilliamps, which is, as you’ve proven, insufficent to activate even theelectronic flaser. Either swap back to incandescent up front, or adddummy-load resistors in the circuit to place a load on the flasher. I’llguess that one ampere or so would be enough. If that’s true, at 13.5 volts,a 13.5 ohm resistor would be needed, and it would dissapate 13.5 watts.Since a 13.5 ohm resistor is non-standard, I’d go with a 15 ohm, 20 wattwirewound resistor (Digi-Key, Radio Shack, etc.). If you want to trysomething more compact, a 20 ohm 10 watt might also do the job – as wouldhanging a bulb somewhere where it can’t be seen.



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