Headlights went out this morning

[99_4Runner]

This morning jump in my Runner to head to work and my low beams are out!:redbrick: I didn't have time to troubleshoot as I was running a little late, so I ended up taking my GF's car. I find it hard to believe that both bulbs are bad as I replaced them less than 6 months ago and they are Sylvania Hyper White Bulbs. I know the first thing to do is check the fuses, anything else I should check while I am under the hood?

 

[TheDurk]

This morning jump in my Runner to head to work and my low beams are out!:redbrick: I didn't have time to troubleshoot as I was running a little late, so I ended up taking my GF's car. I find it hard to believe that both bulbs are bad as I replaced them less than 6 months ago and they are Sylvania Hyper White Bulbs. I know the first thing to do is check the fuses, anything else I should check while I am under the hood?

Just please check fuse with a light or meter, or swap with a known good fuse. I've wasted a LOT of time helping people with fuses that people said 'looked good'. If it really is good, swap bulb for a good one. It is amazing how often they burn out together, and six months is not that short a time.

If it is guaranteed not fuse or bulb, then it is probably either stalk or relay. Post back, and I'll help you chase it. You'll need a test light or meter.

 

[99_4Runner]

Just please check fuse with a light or meter, or swap with a known good fuse. I've wasted a LOT of time helping people with fuses that people said 'looked good'. If it really is good, swap bulb for a good one. It is amazing how often they burn out together, and six months is not that short a time.

If it is guaranteed not fuse or bulb, then it is probably either stalk or relay. Post back, and I'll help you chase it. You'll need a test light or meter.

I cannot look until this evening but I will post what I run across. Thanks for the input.

 

[2014 Warthog]

Ah yes the hyper white bulbs you generally only get 12 months out of them anyway... I liked them but eventually went back to normal bulbs after getting real tired of having one of my headlights burn out every few months constantly

But I bet it is a fuse too with them both going out at once

 

[99_4Runner]

Ok, so it is not the fuses. I replaced the 2 10 amp fuses in the fuse box under the hood and still no low beams. The high beams work fine, just no low beams. Question, there is a relay for the headlights in the fuse box as well, if that was bad would the high beams still work? I am thinking no, but I could be wrong.

 

[02SE]

The high-performance bulbs do burn out quickly, in comparison to a standard bulb. The bulbs are so easy to take out, I'd just pull them and see if the low-beam filaments have failed.

 

[TheDurk]

Ok, so it is not the fuses. I replaced the 2 10 amp fuses in the fuse box under the hood and still no low beams. The high beams work fine, just no low beams. Question, there is a relay for the headlights in the fuse box as well, if that was bad would the high beams still work? I am thinking no, but I could be wrong.

On a '99 without DRL's, you are correct, a bad relay would kill both high and low. Time to make sure of the bulbs. If you don't want to find one to test with, pull the plug off one side and ground the terminal with the blue wire with black stripe. If the other side low beam does not come on, your bulbs are dead.

If it does come on, then we'll move on and test the stalk.

 

[the great him]

my head light relay went out on my a while back, and i still had high beams, but lows were not working.

 

[TheDurk]

my head light relay went out on my a while back, and i still had high beams, but lows were not working.

On a 4Runner without DRL's, the highs and lows are switched on the ground side of the high and low filaments. The relay only provides power to the common filament. If it works on high, it will work on low. Did you have DRL's on that rig? That's a whole different ball of wax.

 

[the great him]

On a 4Runner without DRL's, the highs and lows are switched on the ground side of the high and low filaments. The relay only provides power to the common filament. If it works on high, it will work on low. Did you have DRL's on that rig? That's a whole different ball of wax.

nope. -i should clarify though i had highs when i pulled back on the "flash to pass", other wise i had nothing. swapped relay and boom had my lights back -this was on my 97

 

[TheDurk]

nope. -i should clarify though i had highs when i pulled back on the "flash to pass", other wise i had nothing. swapped relay and boom had my lights back -this was on my 97

Did you ever put the old relay back to see if it was really dead? With the high flash working and heads otherwise dead, that points to an issue in the auto-off circuit. It may have been stuck and then cleared. I stand by what I said. Here is the circuit below (outside chance '97 is different, but this is good '99-'02 w/o DRL); I think any other electric guy would agree with me:

 

[the great him]

it was bad. i swapped it with another 4runners relay and put mine in his, the problem fallowed the relay.

 

[IBallEngineer]

Did you ever put the old relay back to see if it was really dead? With the high flash working and heads otherwise dead, that points to an issue in the auto-off circuit. It may have been stuck and then cleared. I stand by what I said. Here is the circuit below (outside chance '97 is different, but this is good '99-'02 w/o DRL); I think any other electric guy would agree with me:

You rang?

Yes I agree with you, The relay could not have been the problem if ANY lights worked. Even the flash circuit although grounded directly through the stalk MUST have power from the HL Relay.

:rockon:

 

[TheDurk]

it was bad. i swapped it with another 4runners relay and put mine in his, the problem fallowed the relay.

Sorry, I just don't see that as possible. You sure his high flash worked with the bad relay, too? Throw this one in the Weird Electrical Sh!t file, that really big one over there.

 

[the great him]

Sorry, I just don't see that as possible. You sure his high flash worked with the bad relay, too? Throw this one in the Weird Electrical Sh!t file, that really big one over there.

we didnt try that, but his relay worked for me, and fixed my issue. i dont know what to tell you

 

[TheDurk]

we didnt try that, but his relay worked for me, and fixed my issue. i dont know what to tell you

Well, point is you did not have normal highs like the OP does, just high flash. I remain confident relay is NOT his problem. I just can't explain how you could have high flash and nothing else and fix it with a relay change.

 

[TheDurk]

I agree with TheDurk, sounds like the stalk if not bulb, fuse, relay. Pop out the dual filament (HI/LO) H4 bulb on the non-battery side (much easier) and test that one first. Inspect visually for broken filament or metal spray inside inside the glass. Then test electrically: touch across all pairs of terminals with a 9V battery will glow after about a second with fresh battery. Test across all and see what lights up. One pair lights the low beam (the one in the metal cup), the parallel pair lights the high beam, the third lights them both if your battery isn't getting too dead. If bulb is good, check the other side. Loosen battery hold-down to move battery slightly, much easier.

Sure they could both go out at *exactly* the same time but somewhat unlikely unless you hit a HUGE bump (shock) or redlined the crap out of it for extended period (vibration).

If both bulbs good, test the stalk. Over years of use, if it's twisted on with too much force, it's possible to twist it past "ON", to where the lights turn off. Mine will do that if I twist then hold, so I twist it on with just enough force to light the beams without overrunning the contact.

Agree with all that, except your diagram should reverse the pluses and minuses and the common terminal should be labeled 12V COMMON + and not GROUND -.

Thing is, on the two bulbs at once doesn't happen thing--what DOES happen is people just don't notice when the first filament goes, especially lows, and then think both went at the same time when the second goes. The truth is one was out for quite some time.

 

[99_4Runner]

Will check bulbs tonight

Unfortunately due to my commute I cannot check the bulbs until this evening when I get home. I still have hi beams but the dash indicator doesn't come on, flash to pass works as well. Last night I cleaned the connectors, even changed the fuses again. I have a known good H4 Bulb from my bike I will use to test tonight and post my findings.

 

[99_4Runner]

Solved! Thanks for the help!

Replaced the bulbs and low and behold they worked. Freakin $40 bulbs lasted 6 Months, when the cheap blue ones I had lasted almost 2 years!:frusty: Thanks for the help everyone. I definately won't buy those again!

 

[papapoopski]

Both of my bulbs went out at exactly the same time too. I thought it was strange and thought it would have been an electrical problem at first. I was surprised when I changed bulbs and that was it.