Brake Light and Turn Signal Circuits Cause Error in Truck

Question:

i hooked up all the lights for the truck and trailer and i have them all working but inside the truck it says the lamp is out when the blinker blinks or when you step on the brake what could be the problem and do i need a converter for the brake lights and do i need to tap into both brake lights or can i just tap into one?

asked by: Matt

Expert Reply:

Your 2003 Dodge Ram should have a converter on the trailer wiring harness to combine the brake and turn signals on your truck's separate wiring to a combined 2-wire system.

Since your truck thinks there is a bulb out on the trailer I'm guessing the you have LED bulbs. LEDs draw less power than incandescent bulbs so the truck may mistakenly recognize the low draw as a bad bulb. To solve this you can add load resistors # DI34ZR to the wiring. The load resistors which will add additional resistance to the circuit.

expert reply by: Charles S