I just installed LED taillights (brake lights), and my cruise stopped working. Or it would work and cancel after 5 to 20 seconds. I replaced one brake light with a standard incandescent light, and the cruise went back to working.
What I discovered is that LED taillights do not "pull" the 12v brake wire to ground as incandescent lamps do.... it has to do with LED's having a voltage drop of 1.2 volts. So this causes the brake line to "float" at 1.2v instead of being either at 12v or 0v. This "gray area" is enough to trick the cruise control into thinking you have hit the brakes. The solution is to make sure the brake line goes all the way to 0v when the brakes are not pressed.
There are two ways to do this. Make sure that ONE of the brake lights is incandescent. The best looking (most symmetric) is the 3rd brake light.
Another solution is what I did. Wire a 10k ohm resistor across the LED lamp for the 3rd brake light. I got my lamp from superbrightleds.com , and the plastic body has little holes in it. I was able to thread a 1/4watt 10kohm resistor into the body and simply bend the leads down just like the wires that were already on the lamp. Works like a champ. Best of all, I didn't have to splice the load resistors (which get very warm) into any of my wires.
By the way, my flasher don't spend the money for the load resistors for LED turn signals, just install a heavy duty flasher. It won't speed up when the LED turn signal lamps are installed.
What I discovered is that LED taillights do not "pull" the 12v brake wire to ground as incandescent lamps do.... it has to do with LED's having a voltage drop of 1.2 volts. So this causes the brake line to "float" at 1.2v instead of being either at 12v or 0v. This "gray area" is enough to trick the cruise control into thinking you have hit the brakes. The solution is to make sure the brake line goes all the way to 0v when the brakes are not pressed.
There are two ways to do this. Make sure that ONE of the brake lights is incandescent. The best looking (most symmetric) is the 3rd brake light.
Another solution is what I did. Wire a 10k ohm resistor across the LED lamp for the 3rd brake light. I got my lamp from superbrightleds.com , and the plastic body has little holes in it. I was able to thread a 1/4watt 10kohm resistor into the body and simply bend the leads down just like the wires that were already on the lamp. Works like a champ. Best of all, I didn't have to splice the load resistors (which get very warm) into any of my wires.
By the way, my flasher don't spend the money for the load resistors for LED turn signals, just install a heavy duty flasher. It won't speed up when the LED turn signal lamps are installed.
