Forum Discussion

Bear25314's avatar
Bear25314
Explorer
Aug 14, 2016

After replacing truck lights with LED's, TT lights act weird

I have a 2011 F250. I replaced all the marker light bulbs with LED's. Now, when I attach my TT, the marker lights on the TT act differently. The brake lights work fine, however, when I turn on a blinker (either one), all the marker lights begin to blink as well. Also, when I press the brake with the blinker on all the marker lights on the TT come on steady. I am at a loss. Thanks in advance for any pointers.
  • Bear25314 wrote:
    I only replaced the bulbs on my F250. I travel trailer has the original incandescent bulbs. Could it be a ground wire?


    No, it's your truck which wasn't designed to work with LED bulbs. Reinstall the original incandescents and your problem will go away.
  • The flasher circuit now has a much smaller load on it then before. Years ago you needed to swap out the flasher in the truck for one that was compatible with LED lights. I'd look into that. I don't know if you can change them out on the new trucks.
    One way to get around that was to wire a regular bulb in parallel with the LED lights so there was more current draw. This will make the flasher circuit work properly again. The problem is this kind of defeats the point of putting in LED's if you're trying to reduce current consumption. You still get the longevity and cool look of LEDs.
  • I only replaced the bulbs on my F250. I travel trailer has the original incandescent bulbs. Could it be a ground wire?
  • Bear25314 wrote:
    Thanks in advance for any pointers.


    Not all vehicle electrical systems are compatible with LED bulbs in the trailer's exterior lights. My suggestion - reinstall the original incandescent bulbs, 'cause that's what your F250 is designed to power.
  • RoyB's avatar
    RoyB
    Explorer II
    I never wanted to change any of my DOT safety lights out for the LED types as this never was a power consumption issue from my battery banks. All the power to operate the safety lights comes from the truck battery not the trailer batteries.

    The LEDS are very sensitive and low DC voltages probably back feed into things very easy...

    I know my trailer ceiling LED lights sometimes are showing a very dim light even when they are turned off sometimes...

    You may have a hard time tracking these events down haha... Most likely all ground related perhaps...

    Roy Ken

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,189 PostsLatest Activity: Jan 21, 2025