Wicked FX4

I have a 04 f150 all stock and my cruise control will not operate at all. I have gone through the trouble trees and also have checked the stuff from the tsb that was released on this problem and everything came back good with no problems. was wondering if anyone has come across this or has any advice

Mod (Ret.)

Interesting that you brought this up; I just installed an LED 3rd brake light/cargo lamp assembly (smoke lense), and my cruise does not work either. When I press the "on" button on the steering wheel, the dash icon for the cruise does not light up. Does your icon light up in the dash when you press the "on" button?

I read on another forum that another person posted this same problem after installing a 3rd brake light LED assembly. He re-installed the original with a filiment bulb, and it works now. Puzzling to me, as I know LED's use low amperage, but that's when the brake is applied. I'd think that when the brake pedal is off, there would be no current draw, and the cruise should work.

The only thing I can think of is that the cruise circuit "expects" to read a certain amount of resistance through the brake circuit with the brake lights off; a filiment bulb provides a minimal amount whereas the LED would not. This is a guess on my part.

So, have you checked your brake lights for a possible burned out bulb, specifically the 3rd brake light (above the center cab)? Let me know your findings, as this is puzzling me too. My problem may be different from yours, but if you find that you have a burned out brake light bulb, replace it, and your cruise works, it will verify this observation.

Lenn

Wait... So you guys have an icon that comes on when you press the "On" button? Mine does not light up with just that pressed. Only icon I get is when I press the "Set" button to set the speed. Everything with the lighting system on my truck is stock vice the fog lights and everything functions normally.

Good old Bill

I believe the icon lites up after the "set" button is pressed. Just pressing the "on" only satisfies half of the system, still needs what speed to hold to complete the circuit. Bucko, like your thinking, that is exactly how the circuits work to notify us of a bulb out. Haven't thought about that experience in years.

Mod (Ret.)

I am probobly wrong! The icon comes on when you "set" the cruise. Sorry about that.

In any event, my cruise stopped working, and the only mod I did to the truck from the last time it worked was to install LED's in the taillights, and an LED smoke lense 3rd brake light assembly. On another forum, a guy posted that he also experienced his cruise stopped working after installing an LED 3rd brake light assembly.
I can only "assume" at this time that the cruise "activation" circuit is tied to the brakelights. It must look for resistance through the brake bulbs???

In the old days, there was a switch on the brake pedal that would kill the cruise when the brake was applied. These new trucks seem to work in reverse; they won't "activate" unless they see a complete circuit in the brake light circuit.

I hope the original poster checks his bulbs to see if he has a blown bulb, and posts his findings.

Lenn

So if you were to change out the entire tail light assemblies to LED units and the 3rd brake light to ensure that all components were pulling even resistance, shouldn't the system function normally? I remember that with Volvo's, they have a system that will warn when you have a bulb out and WHICH ONE it is via a message in the information center. If the owner didn't get a "Volvo" bulb to replace it, the message would not go away until all of them were changed out with the same brand since the resistance that the bulbs were pulling were slightly varied due to different brand charactaristics. Might our cruise system work the same way?

Good old Bill

Have a hunch that is exactly what Bucko is saying. The three bulbs have a rating of X resistance combined and that has to be present for the cruise control to be satisfied, when a higher amperage is detected (brake lites on) it disengages the cruise control. I think!

Mod (Ret.)

I'll prove this theory tonight; I am going to remove the LED 3rd brake/cargo unit I installed Saturday, then test the cruise. If it's still not working, I'll remove the LED tail light bulbs and try again. It has to be one of those two combinations, as the cruise worked a few months back, and all I did from that time forward was to install LED's in the taillight housings and install a new LED 3rd brake/cargo light assembly.

On the F150ONLINE forum, a poster there mentioned his cruise stopped working after he installed an LED 3rd brake/cargo lamp assembly. He did not mention if he also installed LED's in his tail light housings though.

I'll post my findings tomorrow.

Thanks for the responses guys.

brub27

Holy crap I thought I was the only person on here that had that problem, isn't it crazy that a 3rd brake light swap overrides the cruise control, it sucks but I like my light

brub27

It's the 3rd brake for sure no doubt, I have taken mine out for when I go on long hauls and put the stock one back in, cruise works fine.