No headlights (Low beam) !!!

[TNJYOUNG]

Good evening everyone,

I was at a friends house tonight and I left to head to another party. The sun was almost down. As it got darker, I realized that I couldn't see as well as normal. I pulled off the road and noticed that my low-beam headlights were not working.

I cam home, popped the hood and began to swap out fuses (20A) with other fuses that I did not need as much as headlights (like rear windshield washer). To my surprise, the headlights never came on.

Anyone ever have this happen? More importantly, any ideas as to what may be up? If I remember correctly the low beams are in slots [16] and [11], both (20A).

Kind regards,
Jason

 

[Rocket Man]

Switch? Bulbs, maybe one was already out and the second one just went? Are you sure you put good fuses in the correct place?

 

[gooffeyguy]

Make sure the switch is still on auto mode. Try turning the switch to the other settings and see what happens.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[TNJYOUNG]

Make sure the switch is still on auto mode. Try turning the switch to the other settings and see what happens.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

I have already done that. :-(

 

[Doubeleive]

so more details??
high beams working?
instrument cluster lights working?
tail lights?
marker lights?
blinkers?
if everything else is working then you have one or more bad low beam bulbs, bulb harness/connector or relays (in fuse box under the hood) or you have a bad ground in the low beam's
if you have no high or low beam then perhaps a bad light switch, luckily there rather cheap

 

[TNJYOUNG]

so more details??
high beams working?
instrument cluster lights working?
tail lights?
marker lights?
blinkers?
if everything else is working then you have one or more bad low beam bulbs, bulb harness/connector or relays (in fuse box under the hood) or you have a bad ground in the low beam's
if you have no high or low beam then perhaps a bad light switch, luckily there rather cheap

Thank you all for your responses.


ALL electronic components aside from low beams work. There are (3), what I would call "notables" about all of this.

1. I had my car washed yesterday. (I am sure this had little if anything to do with this, but thought I'd mention it)
2. When I got the vehicle it already had 1. a trailer brake installed, additional fog lamps installed. (I cut the wires to the fog lamps and taped off the wires underneath very, very securely)
3. The passenger side front electric seat motor would only tilt the seat backwards, but it would not return to the upright position. I pulled off the seat back, found the motor, cut the wires, reversed the wires, and then twist-capped them off. Then the seat would tilt up, but not back. I was fine with this as I got the seat to the correct position and told the family and no one touches the adjustment. This was over a year ago. BUT the car wash place did drive that seat all the way forward to vacuum. This had not been done in quite a while--or ever. I drove the seat back to the standard position once I got back in my Tahoe.

So, high beams work, factory fog lamps work, and as of the day before yesterday I had "both" low beams working fine. To think that both bulbs blew at the same time, to me, seems like a stretch.

 

[wjburken]

Thank you all for your responses.


ALL electronic components aside from low beams work. There are (3), what I would call "notables" about all of this.

1. I had my car washed yesterday. (I am sure this had little if anything to do with this, but thought I'd mention it)
2. When I got the vehicle it already had 1. a trailer brake installed, additional fog lamps installed. (I cut the wires to the fog lamps and taped off the wires underneath very, very securely)
3. The passenger side front electric seat motor would only tilt the seat backwards, but it would not return to the upright position. I pulled off the seat back, found the motor, cut the wires, reversed the wires, and then twist-capped them off. Then the seat would tilt up, but not back. I was fine with this as I got the seat to the correct position and told the family and no one touches the adjustment. This was over a year ago. BUT the car wash place did drive that seat all the way forward to vacuum. This had not been done in quite a while--or ever. I drove the seat back to the standard position once I got back in my Tahoe.

So, high beams work, factory fog lamps work, and as of the day before yesterday I had "both" low beams working fine. To think that both bulbs blew at the same time, to me, seems like a stretch.

As for the seat, I would suspect a faulty seat switch. These are known to fail and are easy to change for $70.

Have you swapped relays for your low beams? Do you see any signs of corrosion in your fuse block under the hood? I believe it is @Doubeleive that advocates a controlled pop to the fuse block under the hood.

 

[Rocket Man]

I vote relay if I was guessing. Possible corrosion on the legs, or corrosion in the fuse box like Wade mentioned.

 

[TNJYOUNG]

I am going to go by the auto parts store and buy 2-3 relays. They appear to be cheap. This seems to be the most common suggestion (and the only one that makes sense to me). I will also, give a controlled "pop" to the fuse box for what it's worth. Thanks again everyone. I will post updates later today.

 

[TNJYOUNG]

So....I went to three auto parts stores locally and NONE of them had the relays. They wanted between $14.99 and $21.99 for them, to boot. They told me they could order them and that they would be there on Tuesday. So I dialed up my Amazon prime account and ordered 4 of them for $30 and some change ($7.99 each) and they will be on my doorstep on Tuesday.

It is so hard for me to believe that a vehicle that ran for 6-7 years and sold millions would not be a stock item for the auto parts stores. As as much as I prefer to support brick & mortar retail, that price was not even close!

I will update you all on Tuesday evening.

 

[TNJYOUNG]

...I am completely speechless. I got to thinking about the suggestion of a controlled "pop", so I took my flashlight outside, popped the hood, and took a hammer and gave a firm but controlled "tap" and voila....my lights came back on just as pretty as you please. Still cannot believe this. OMG!

 

[Rocket Man]

...I am completely speechless. I got to thinking about the suggestion of a controlled "pop", so I took my flashlight outside, popped the hood, and took a hammer and gave a firm but controlled "tap" and voila....my lights came back on just as pretty as you please. Still cannot believe this. OMG!

Smacked the relay or fuse box?

 

[Doubeleive]

nice, I wouldn't have used a hammer though the palm of your hand works fine, but hey it worked

 

[PPV12HOE]

It's the little things that can drive ya crazy...

 

[wjburken]

nice, I wouldn't have used a hammer though the palm of your hand works fine, but hey it worked

Need to be a little more clear on the @Doubeleive / Fonzy method I guess!

 

[wjburken]

...I am completely speechless. I got to thinking about the suggestion of a controlled "pop", so I took my flashlight outside, popped the hood, and took a hammer and gave a firm but controlled "tap" and voila....my lights came back on just as pretty as you please. Still cannot believe this. OMG!

Good to hear!

 

[TNJYOUNG]

Smacked the relay or fuse box?

Fuse box.

 

[Kelly Craft]

Good evening everyone,

I was at a friends house tonight and I left to head to another party. The sun was almost down. As it got darker, I realized that I couldn't see as well as normal. I pulled off the road and noticed that my low-beam headlights were not working.

I cam home, popped the hood and began to swap out fuses (20A) with other fuses that I did not need as much as headlights (like rear windshield washer). To my surprise, the headlights never came on.

Anyone ever have this happen? More importantly, any ideas as to what may be up? If I remember correctly the low beams are in slots [16] and [11], both (20A).

Kind regards,
Jason

Jason,

I recently had the same issue with my 08 Yukon, that is what brought me to this forum. My low beams went out while driving down the interstate an night!! took me a a while to figure out I could just hit the high beams and go on, just had to let everybody get mad at me. I fought this for a long time. They would come and go for a while then just stopped completely. I tried everything and scoured all of the forums I could find no luck. I even went to a salvage yard and bought the guts for the fuse/relay box and swapped it still nothing. Eventually I figured out the BCM supplies the ground input to all of the relays in the relay box to trigger them so i ran a jumper wire from the fog light relay to the low beam relay then i just had to turn on fog lights to get low beams on. I went like that for a while. Then other things began to stop working, amp for radio, blower motor, and rear turn signal sometimes worked sometimes didn't . Noticed the gremlins would usually come after a car wash. I got very determined one Saturday and tore into it. What I found was under the the fuse relay box the wire loom splits and goes several directions therefor the plastic loom cover ends and new ones go other directions. right at point it lays on the raw edge of the fender. I had 3 wires that were broken a several that were worn bare. I repaired all of the damage and taped it up. Then I got a piece rubber hose about 12" long and split it down the side and slipped it over the sharp edge of the fender. Wala no more problems and everything worked as it should. You have to take the whole fuse assembly out and get it out of the way then lift the wire harness up to look under it.

 

[TNJYOUNG]

Jason,

I recently had the same issue with my 08 Yukon, that is what brought me to this forum. My low beams went out while driving down the interstate an night!! took me a a while to figure out I could just hit the high beams and go on, just had to let everybody get mad at me. I fought this for a long time. They would come and go for a while then just stopped completely. I tried everything and scoured all of the forums I could find no luck. I even went to a salvage yard and bought the guts for the fuse/relay box and swapped it still nothing. Eventually I figured out the BCM supplies the ground input to all of the relays in the relay box to trigger them so i ran a jumper wire from the fog light relay to the low beam relay then i just had to turn on fog lights to get low beams on. I went like that for a while. Then other things began to stop working, amp for radio, blower motor, and rear turn signal sometimes worked sometimes didn't . Noticed the gremlins would usually come after a car wash. I got very determined one Saturday and tore into it. What I found was under the the fuse relay box the wire loom splits and goes several directions therefor the plastic loom cover ends and new ones go other directions. right at point it lays on the raw edge of the fender. I had 3 wires that were broken a several that were worn bare. I repaired all of the damage and taped it up. Then I got a piece rubber hose about 12" long and split it down the side and slipped it over the sharp edge of the fender. Wala no more problems and everything worked as it should. You have to take the whole fuse assembly out and get it out of the way then lift the wire harness up to look under it.

I feel so stupid! First of all, when I "tapped" the fuse box and thought it worked...well it didn't. Turns out, I had the high beams on when I made my confirmation. When I got in the Tahoe this morning, yes the lights came on, but they were on bright. When I pulled the yoke back to go to low-beams, the lights went off. Now I am back to waiting on the relays to arrive tomorrow. Hopefully I will not have to go to the depths that you did for a fix, but thank you for the story as that may be my next steps.

 

[Doubeleive]