Incandescent to LED tail lights. Flasher issues.

Post by emmett518 » Sun Dec 25, 2022 2:24 pm
Two weeks ago, I drove the pallet forks on my Deere tractor through the left, rear, plastic, taillight lens on my F150. Luckily, I was moving very slowly, and stopped when I heard crunching noises, so no body damage occurred.

Since I did not want to spend $300 on a factory replacement, I searched online, and found a used, factory OEM one locally for $50.

That unit came with LED bulbs, so since the entire lens / housing / wiring harness and bulbs can be replaced as one unit by plugging one connector, I just substituted the new assembly for the old. The old unit had incandescent bulbs.

When i engage the blinkers, the flasher cycles very quickly, and the cab indicators do not light on the left. Right is normal.

What's the deal?

Do I have to make all of the tail and front marker lights LEDs on left and right, and change the flasher? Can you mix incandescents and LEDs? Or can I just change the flasher?

And if it all has to be upgraded, does it make any sense to do so? If I upgrade all to LEDs, does this mean I'll likely never get sodomized by the inspection people when they discover a tail light out?

Thanks

 

The LEDs don’t pull enough power and thus the truck thinks there is a bulb out, hence the fast flashing. LEDs on one tail light only is a recipe for problems and can’t look too good either. Need to go back to all incandescent or all LED and make the appropriate modifications in forscan.

 

The easiest and cheapest fix is to install incandescent bulbs in your new taillamp. If you want to keep LED bulbs, you'll need to make some software adjustments. LED bulbs don't pull much current, so the control module in your truck that was originally equipped with incandescent bulbs thinks you have burned-out stop/turn signals, and the fast flashing is meant to alert you (this has been a feature of American cars for decades).

 

Aren't there LEDS bulds that have a built resistor?

 

Don’t know where you live but if there is a Dealers Truck close to you go there. They will sell you what you need.