New LED's now no cruise
New LED's now no cruise
Just installed LED tail lights, now I don't have cruise control. Checked fuses and circuits, all good. How can I retain these lights and get my cruise control back?
Senior Member
Joined: Aug 2010
Posts: 779
Your cruise doesn't work or the cruise light on dash isn't lighting up?
the only sure way to determine if the lights are the culprit is to remove the LED tail and reinstall the stock lights and see if the cruise control works. If so then add some in line resistors. Make sure to buy high quality ones though so you don't burn your rig to the ground.
These don't use CAN BUS so generally the computer couldn't care if you have LED's or not. I have LED tails, lower bumper lights, everything up front, literally every bulb in my rig is LED and I've never had any issues.
These don't use CAN BUS so generally the computer couldn't care if you have LED's or not. I have LED tails, lower bumper lights, everything up front, literally every bulb in my rig is LED and I've never had any issues.
I had problems with my cruise control for a while, and all of a sudden the radio and heater controller would just die on me, no power nothing. Then the next day everything would work again. The dealer put it down to a faulty roll over sensor. Apparently it was the only sensor on the network that was showing a fault. It's not happened for a long while now though, and i've got a new sensor, so will be having that installed soon. Probably unrelated to your lights, but my cruise control would stop working, or the light would just come on but wouldn't operate etc etc... (mines 08-09 model).
Senior Member
Joined: Feb 2015
Posts: 1,633
From: Birmingham (UK)
Definitely is the LEDS, reason is the light circuit is directly monitored by the cruise control (CC) system, the moment the stop/brake light turns ON it pulls the lamp and the CC sense line up to 12V. When the lamp is OFF i.e. not braking the resistance of the lamp pulls the CC sense line back to 0V (ground) The problem with LEDs is that at low voltages they are effectively an open circuit so the CC sense line "floats" back-up to 12V hence the system interprets this as braking and cancels the cruise control.
You're going to ask what resistor value?
I'd say the higher ohms the better as power dissipated is V²/R which is 144/R, so 144R (Ohms) equates to 1Watt which is a lot. A 620R 1/4 Watt resistor would be good if you can get away with it, I suspect though from other comments its going to have to be a lot lower may be 200R 1 Watt, 100R 2 Watt or even 56R 3Watt but watch the heat!
Think the original lamp/bulb is 27W x 2 and so the CC system has to be able to cope with just one lamp working (bet if both were out the CC would stop working again) 27W is effectively a 5R resistor but the bulb measures less than 1R when cold!
Also I think you'll only need one resistor in the circuit, my electronic guess is that either a 33R 5Watt or 100R 1.5Watt will work.
Let the forum know what works!
You're going to ask what resistor value?
I'd say the higher ohms the better as power dissipated is V²/R which is 144/R, so 144R (Ohms) equates to 1Watt which is a lot. A 620R 1/4 Watt resistor would be good if you can get away with it, I suspect though from other comments its going to have to be a lot lower may be 200R 1 Watt, 100R 2 Watt or even 56R 3Watt but watch the heat!
Think the original lamp/bulb is 27W x 2 and so the CC system has to be able to cope with just one lamp working (bet if both were out the CC would stop working again) 27W is effectively a 5R resistor but the bulb measures less than 1R when cold!
Also I think you'll only need one resistor in the circuit, my electronic guess is that either a 33R 5Watt or 100R 1.5Watt will work.
Let the forum know what works!
Senior Member
Joined: Oct 2013
Posts: 157
Definitely is the LEDS, reason is the light circuit is directly monitored by the cruise control (CC) system, the moment the stop/brake light turns ON it pulls the lamp and the CC sense line up to 12V. When the lamp is OFF i.e. not braking the resistance of the lamp pulls the CC sense line back to 0V (ground) The problem with LEDs is that at low voltages they are effectively an open circuit so the CC sense line "floats" back-up to 12V hence the system interprets this as braking and cancels the cruise control.
You're going to ask what resistor value?
I'd say the higher ohms the better as power dissipated is V²/R which is 144/R, so 144R (Ohms) equates to 1Watt which is a lot. A 620R 1/4 Watt resistor would be good if you can get away with it, I suspect though from other comments its going to have to be a lot lower may be 200R 1 Watt, 100R 2 Watt or even 56R 3Watt but watch the heat!
Think the original lamp/bulb is 27W x 2 and so the CC system has to be able to cope with just one lamp working (bet if both were out the CC would stop working again) 27W is effectively a 5R resistor but the bulb measures less than 1R when cold!
Also I think you'll only need one resistor in the circuit, my electronic guess is that either a 33R 5Watt or 100R 1.5Watt will work.
Let the forum know what works!
You're going to ask what resistor value?
I'd say the higher ohms the better as power dissipated is V²/R which is 144/R, so 144R (Ohms) equates to 1Watt which is a lot. A 620R 1/4 Watt resistor would be good if you can get away with it, I suspect though from other comments its going to have to be a lot lower may be 200R 1 Watt, 100R 2 Watt or even 56R 3Watt but watch the heat!
Think the original lamp/bulb is 27W x 2 and so the CC system has to be able to cope with just one lamp working (bet if both were out the CC would stop working again) 27W is effectively a 5R resistor but the bulb measures less than 1R when cold!
Also I think you'll only need one resistor in the circuit, my electronic guess is that either a 33R 5Watt or 100R 1.5Watt will work.
Let the forum know what works!
Wrong.
You forgot to divide by pie....lol