Headlamps, hi and low beam, stopped working

[Mike Pyne]

On 11/27/2016 at 12:51 PM, natesimpson74 said:

2014 GMC Sierra 1500, Last night I got into my truck and neither my high beams or low beams would turn on in my truck. The fog lights, turn signal/marker lights, and tail lights all work. I tried auto and on on the switch. I tested for power at the headlight fuse and did not have any with the headlights turned on. The light on the dash turns on indicating that the headlights are turned on.

 

Any ideas where to look? I cant seem to find anything that shows where a headlight relay is. What links both high and low beams other than the BCM? Of course my truck is 4000 miles out of warranty.

 

Any help is appreciated! Thank you.

 

FYI:  I found the information below in a post from member “tbarn”. 

 

Low beams are wired direct from bcm. High beam control relay is in the underhood fuse/relay box which are "non-serviceable Printed Circuit Board (PCB) relays and are internal to the block".

 

The headlamps may be turned ON in 3 different ways:

•When the headlamp switch is placed in the ON position, for normal operation
•When the headlamp switch is placed in the AUTO position, for automatic lamp control
•When the headlamp switch is placed in the AUTO position, with the windshield wipers ON in daylight conditions, after a 6 second delay
The BCM will also command the low beam headlamps ON during daylight conditions when the following conditions are met:

•Headlamp switch in the AUTO position
•Windshield wipers ON
•Vehicle in any gear but PARK
When the BCM commands the low beam headlamps ON, the vehicle operator will notice the interior backlighting for the instrument cluster and the various switches with backlighting control will dim to the level of brightness selected by the instrument panel dimmer switch.

The body control module (BCM) monitors three signal circuits from the headlamp switch. When the headlamp switch is in the AUTO position, all three signal circuits are open. When placed in the AUTO position, the BCM monitors inputs from the ambient light sensor to determine if headlamps are required or if daytime running lamps will be activated based on outside lighting conditions. When the headlamp switch is placed in the OFF position, the headlamp switch headlamps OFF signal circuit is grounded, indicating to the BCM that the exterior lamps should be turned OFF. With the headlamp switch in the PARK position, the headlamp switch park lamps ON signal circuit is grounded, indicating that the park lamps have been requested. When the headlamp switch is placed in the HEADLAMP position, both the headlamp switch park lamps ON signal circuit and the headlamp switch headlamps ON signal circuit are grounded. The BCM responds to the inputs by illuminating the park lamps and headlamps. When the low beam headlamps are requested, the BCM applies B+ to both low beam headlamp control circuits illuminating the low beam headlamp.

[Jennifer Watson]

I would like in on this issue as well. Jhon, will this be a recall because this is ridiculous? Just got home from traveling 8 hours to go pick up our 2018 Sierra Denali 3500 and halfway home we realized the headlights and high beam won’t work. Everything else is fine. Please reply. 

[Firefighter344]

Did anyone figure out this issue? I know it's older. But my 2014 gmc sierra has done the same thing. I loose my driverside light and a few days later it will randomly come on and then go back out. And the passenger side is starting to do the same. And gm is unwilling to be of any assistance.

[RMiller3]

Did anyone identify what is causing this issue?  This issue just happened to me.  Headlights don't work on low beam or high beams, the fuse is good in spot #59 in fuse box under hood.  Both headlights were replaced in the last year because they were so hard to see with.  I don't think I received much improvement.  The only way I can see is using fog lights.  No service departments are open.  I don't know about anyone else, but this is a huge safety issue that needs to be addressed by GM.

 

[Antoine Scuba]

Same happen to me. 2014 GMC pickup 1500. Fuse #58 is the correct one, triple legs 10A. and it's good, so maybe I will have to change light bulbs again, not even 6 months old arhhhhhhhhh.

[cabindweller156]

How about GM step up and fix this issue with their trucks? Obviously its a HUGE problem.. Doing it on my POS truck also. Tell you what, I have been a chevy owner for over 5o years. No more.. I am done with Chevy and the crap they make now.

[2015GMCSierra1500]

GM, this headlight issue is now the 5th reason I will not be buying one of your trucks ever again. There are hundreds of people with this issue, across hundreds of models and years. No help, no answers.

 

I finally changed both bulbs out. Only one was actually burnt out though. The driver side was easy, but the passenger side made me want to kill every engineer that had anything to do with this truck's design. Only an hour of my time and 10 different tools, removing a dozen parts TO CHANGE A BULB. Thing better last.

 

**** you, GM. **** you and your overpriced nonsense.

 

(2015 GMC Sierra 1500)

[Sam Steele]

I am having the same problem with a 2015 sierra 2500. Bulbs both good, fuse good, still no headlights. When tested, they sometimes are showing 12.4 volts, then suddenly just 6 volts.  When it has 12 volts, and the bulb is plugged in, it lights for a second then goes out and voltage is 6 volts again.

[Bamf1332]

Just got in truck and realized my lights weren’t working. After shutting truck off and the. Restarting it a minute later I can turn lights on if I put switch into ON, but only if I do it before shifting out of park. Once I shift out of park I cannot manually turn them on if I didn’t prior. My lights run all the time due to mine being a Canadian model originally. Is this looking like a BCM issue or maybe just a switch. Newer to the Sierra trucks