jas8346

i was thinking about replacing my 3rd brake light along with both my tail light bulbs with LED bulbs. i found a complete replacement for my third brake light for $25, but i haven't been able to find just LED bulb replacements for my tail lights (both brake and reverse lights). i've been on ebay and i'm pretty sure i can get them on there if i knew the part number. does anyone know the part number for the brake and reverse bulbs? also, if anyone has done this or has some good links please share, thanks!

Mod (Ret.)

http://superbrightleds.com/

But be aware of two problems. 1) your cruise control will stop working if you use the 3157 LED bulbs to replace your brake/parking lamps. Reverse lamps would not affect the cruise. 2) You will need a low current flasher, as your current turn signal flasher will blink at ludicris speed. You can find this flasher for sale on the same web site.

If you want LED parking/brake lights, buy the entire taillight assembly from a source that has load resistors in their circuit; this way your cruise control will still work.

Use the search, this has come up many times (cruise control failure with LED bulbs).

jas8346

so if i buy the entire tail light assembly i shouldn't have a problem as long as they have load resistors in their circuits, just remove oem and plug led tail lights? is this true for the 3rd brake light as well? do most tail light assemblies have load resistors in their circuits? thanks!

Mod (Ret.)

You can buy any third brakelight assembly and install; will have no effect on the cruise control. As to tailight assemblies, best to contact the seller/manufacturer and ask them. Some have posted here that they have installed a certain brand LED assembly, and the cruise worked. Offhand, I do not recall which ones. An advanced search on this forum will net you those links.

J-625

i have replaced every light on my truck with led except for the dash lights and i have never had any trouble with the cruise control...i bought an electronic blinker control from advance auto parts to get rid of the fast blink. i buy all of my leds from www.superbrightleds.com

Mod (Ret.)

I'm also betting you used LED complete taillight assemblies with built in load resistors, correct?, That, or you installed load resisters into your wiring.

If you installed just a 3157 bulb (LED bulb for brake/parking) in your existing stock taillight housings, there is no way your cruise control would work, unless you or a previous owner installed a load resistor into the stock brake light wiring. The cruise control circuit detects a voltage increase in the brake circuit when brakes are applied to disable the cruise. When the brakes are not applied, the cruise circuit detects a certain resistance (wiring and bulb filiments are included in this), which allows the cruise to be turned on/activated. LED bulbs without a load resistor cause this resistance to be too low in the 04 to 08 Ford truck models, which does not allow the cruise to turn on.

So, either your truck is not an 04-08, or you have load resistors, or you have LED taillight assemblies installed with built in load resistors (the good ones come with these built into their circuit boards), rather than just rear LED bulbs installed in your stock taillight assemblies.

firefighter

How do the tail lights effect the cruise control?

8up

Take a look at www.autolumation.com

Mod (Ret.)

Hmmm; perhaps a larger font, and bolded from my previous response:

"The cruise control circuit detects a voltage increase in the brake circuit when brakes are applied to disable the cruise. When the brakes are not applied, the cruise circuit detects a certain resistance (wiring and bulb filiments are included in this), which allows the cruise to be turned on/activated. LED bulbs without a load resistor cause this resistance to be too low in the 04 to 08 Ford truck models, which does not allow the cruise to turn on."

J-625

i dont know what to tell you..only thing i can think of is maybe when i switched the blinker relay out that is effecting it some how?. mine is an 07 i bought it with 3 miles on it there is no load resister. i have aftermarket tailllights but they r just the housing, 3157 led lights front and rear. i understand what u r saying about the cruise control to be honest with you im not sure how it still works but it does...i have pics if u care to see all the leds?.