October 19, 2017 at 11:41 pm #176977
First let me apologize for the length of this post but I want to include all of my experiences with LED bulbs for others to read.
I had a 2011 Supercab in which I installed Novsight LED headlights and fog lights and they worked great with no problems. I traded the 2011 in for a 2015 Supercrew and installed LED headlight lamps, fog lights and a pair of switchback front turn signal/running light bulbs. The 2015 came with LED rear lights as it also has the blindspot radar system. The switchback bulbs caused hyperflash at the dash turn indicators but the front turn signals did not work nor did I have the white function of the switchback bulb when it should have been in a running light mode. The rear turn signals continued to work fine though. I also had an issue with one low-beam headlight going out after several minutes but it would come back on again when I cycled through the light switch from auto light to the headlights ‘always on’ position. The fog lights and high-beams always worked fine AND if the truck was not running but the ignition was on everything worked perfectly. The problems existed only when the truck was running and the vehicle’s computer was operating.
I installed resistors on the turn signal circuit wires and this cured the problem of the hyperflash at the dash turn indicators but the front turn signals STILL did not work. I also still did not have the white function of the switchback LED bulb in the running light mode and the low-beam headlight would still go out after a few minutes. I put resistors inline of the running lights and also installed plug-in resistor harnesses for the low-beam headlights. The front turn signal/parking lights still did not work with the vehicle running although the low-beam headlights did work for a longer period of time before the one headlight would turn off.
While rersearching this problem I read online that Ford had a recommended service bulletin that stated that the ‘lamp out’ function of the Body Control Module could be programmed to ‘off’ and that did solve the online poster’s issue of wacky problems when using LED lights in his vehicle. I went to the dealer where I bought my truck and showed them the bulletin. They accessed the Body Control Module but there was no ‘lamp-out’ function on the 2015 F150 in the computer setup so there was nothing to turn off to solve the problems with using LED lights.
I have since removed the turn signal/running light switchback LED bulbs and their resistors and reinstalled the old incandescant bulbs. But, not willing to give up the brightness and improved lighting qualities of the LED headlights I am still trying to find a solution to the one low-beam headlight going out after about 15 minutes of driving.
Since electrical current is at it’s strongest in colder weather I am expecting that once warm weather comes around and the current drops there will be no problem with the computer shutting down the one LED low-beam headlight but that just doesn’t cut it for right now when you need both headlights in the Winter weather.
There HAS to be a solution to all of this since emergency and police vehicles use a lot of LED lights and they function correctly…
So, has anyone got any ideas?
October 21, 2017 at 3:03 am #177106
October 25, 2017 at 5:09 am #177711
I just installed LED headlights and fog lights in my 2014 GMC Sierra SLE in an attempt to improve the “dome of darkness” OEM headlights. I don’t know if Chevrolet’s headlight arrangement is similar to the GMC’s headlights, but I thought I would mention my experience just in case. I did not replace my turn signals or brake/tail light bulbs because I have battled the computer’s current sensor in the past and it was a pain.
Regarding the headlights, I bought my headlights from Xenon Depot. They have a very good reference on what must be done to make the LED headlights work properly. On GMC trucks that do not have the “signature” LED daytime running lamps, the low beam bulb (or the ONLY bulb on the idiotic GMC design) is used at a reduced voltage for the DRL function. The lower voltage is generated by pulse width modulation (PWM)–basically, the power is turned on and off rapidly so the “average” voltage is about 11 volts for the DRLs. From reading the TSB regarding headlight complaints, it appears that even the normal headlight operating voltage is still a PWM waveform. While the halogen bulbs don’t care about the PWM signal (the filament cannot react quickly enough to see the flickering), the LED bulbs don’t like it at all. Xenon Depot sells a separate “CAN Bus” kit for their headlights that stabilizes the voltage to a constant level that the LED headlights don’t mind. While it is somewhat of a misnomer (the module doesn’t connect to the CAN bus at all), it does fix the headlight flickering problem. When I tried installing an LED headlight bulb without the module, it turned on and off randomly. In summary, if you do not have the signature LED lighting on your truck, you may be fighting the PWM waveform problem.
Just for anyone else considering an LED bulb swap, the LEDs work much better on the low beam setting than the OEM halogen bulbs did (at least on my GMC). Of course, the “veil of blackness” still descends (you can’t fix that poor design with a bulb swap), but you do get some more peripheral lighting. The LED fog light swap made a very big difference in visibility. Unfortunately, on the high beam setting, the LED bulbs don’t have the focused beam offered by the halogen bulbs, so your distance vision is definitely worse. You need to be very careful to install the LED bulbs with the LEDs in the correct position (read the instructions) or you will have a very strange beam pattern.
- This reply was modified 3 weeks, 2 days ago by gmctc.
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