Brights / high bemas not working and I've tried to search and figure this out... (1 Viewer)

[FlyingJ]

I have a U.S. 2008 Land Cruiser and the brights aren't working. The blue colored bright indicator on the dash lights up, but no brights come on.

I've checked the bulbs and fuses (15a under the hood) and they all look fine.
I swapped the relays for "Head HI" and "Head LO". And I'm not seeing any difference in headlight behavior. I don't know much about relays. Next to that relay is the DRL No 4 relay that I am guessing is daytime running lights. I don't know how to check these, and am wondering if anyone here has any advice.

All my searches here seem to relate to problems people have with brights after doing some kind of electrical or other car mods/fixes.

Mine seem to have just stopped working.

I'm happy to answer any questions to clarify or go test/troubleshoot to try to get to the bottom of this. Thanks for any help!

J

 

[KLF]

There should be a little finned box in the cavity behind the right (pass side) headlight, in front of the air box. This is the resistor for the DRL, which uses the high beam bulbs. Maybe this thing has burned out and this kills the high beams? Complete guess on my part. No idea how to test it, but maybe it's in the wiring diagrams what's inside that little box.

 

[Sandroad]

Per @KLF, you should be able to confirm the high beams can light up if the DRLs work. I wonder if there is a corroded connector somewhere. Any other electrical problems or water inside?

 

[FlyingJ]

Per @KLF, you should be able to confirm the high beams can light up if the DRLs work. I wonder if there is a corroded connector somewhere. Any other electrical problems or water inside?

Thanks all for jumping in to help. It actually appears that the DRLs are NOT working.

 

[lx200inAR]

Have you checked the bulbs. Someone else recently had an electrical issue that blew all their bulbs at the same time. Either try a new bulb or test the voltage at the high beam bulb sockets.

 

[bloc]

Per the wiring diagrams, a burned out DRL resistor shouldn't impact normal high-beam operation.

@FlyingJ do you have a multimeter and know how to use it? I'd be focusing on the socket for the high beam relay and whether they are seeing the correct signals.

I'm attaching the relevant part of the diagram from a 2008 LC. The operation is a bit convoluted.. It appears when you turn on the low beams it engages "DRL No. 4" relay which is what provides the ground to both high beams. Then when you ask for high beams, the high beam relay provides the +12v, through both "Head HI" fuses, then to the bulbs.

I'm not entirely sure if the DRL portion of the diagram is accurate. If it is, it seems when they are on the high beam relay would need to be triggered, which sends +12v to the LH high beam, then the power goes through the ground wire to a junction at the DRL 4 relay (which is off), then to the RH bulb (backwards, in a way), then on to the DRL resistor (to provide resistance on the ground leg to step down voltage and get the DRL effect) through the non-energized leg of the DRL no 3 relay.

I could have all of that wrong..

But basically, you need to know how to use a multimeter to test the different sockets in the fuse block to figure out what's going on. You having tried swapping the high and low relays is good troubleshooting, now I'd be testing the trigger wire to the high relay. Socket 1. Should see ground when the high beams are triggered.

Or, with high beams enabled via the column stalk, put a jumper into sockets 3 & 5 of the high beam relay spot, and see if they turn on.

 

[LX Cruiser]

Have you checked the bulbs. Someone else recently had an electrical issue that blew all their bulbs at the same time. Either try a new bulb or test the voltage at the high beam bulb sockets.

That was me. Voltage would randomly spike to >17V. Burned all my headlight bulbs without tripping any fuses or anything. I replaced the alternator, and it has been quiet the 2k miles since.

 

[FlyingJ]

Have you checked the bulbs. Someone else recently had an electrical issue that blew all their bulbs at the same time. Either try a new bulb or test the voltage at the high beam bulb sockets.

I did check the bulbs and they all look fine.

 

[FlyingJ]

To answer user Bloc's question: I don't have a multimeter and that sounds a bit above my level of troubleshooting but may see if I can find someone who can help with that.

So here is some additional info...

The daytime running light don't work. In the evening then the auto lights turn on, I get:

Driver side low beam working (the light on the outside)
The fog lights will work if on.
If I pull the stick for high beams the fog lights turn off and the drivers outside beam stays on. No brights light up.
Pushing the stick forward to leave high beams on, nothing happens. The driver beam stays on and so do the fog lights if they are already on. (I need to double check that.)

Again, thanks to everyone who is taking the time to help me out! I will keep everyone posted on this mystery tale!

 

[bloc]

So stalk forward doesn’t trigger the blue high beam indicator on the dash?

The fog lights disabling when the high beams turn on is normal behavior.

 

[KLF]

Maybe the stalk switch has failed?

 

[Sandroad]

And just FYI, on my ‘17 the DRLs operate in the Auto switch position and not in the Off position.

And now that I fully read the post and diagram from @bloc, I’ll take a WAG and suggest a failed DRL relay.

 

[lx200inAR]

I think the fog bulb is the same size as the high beam (at least on non LED vehicles). Could swap the bulb that way.

 

[FlyingJ]

Shoot, I edited my post above to clarify that when I pull the sick back, the fog lights turn off, but the brights don't turn on.

And I'll double check this when I am near the car but I believe I get the blue dash bights indicator when I push the stick forward.

 

[FlyingJ]

OK, here's my big shameful public apology post to my own thread...

I did a better job at checking the bulbs and indeed three of them were burnt out. I hade to take them out of the car and bring them inside for much closer inspection and a friend did a continuity test for good measure. Yeah, three bulbs replaced and all is working properly now.

I don't know what blew three bulbs all of a sudden but here we are.

I leave this up as a cautionary tale, and a bit of public self-shaming.

Thank you all who took the time to help me figure this out!

 

[bloc]

As mentioned above by @LX Cruiser all of his bulbs went out as a result of his alternator intermittently spiking voltage above 17 while it was apparently failing. IIRC they had other symptoms at the same time though.

Maybe consider keeping an eye on the in-cluster voltmeter. Or if you burn out more bulbs do some more precise testing.

Glad you got lighting back though.

 

[FlyingJ]

As mentioned above by @LX Cruiser all of his bulbs went out as a result of his alternator intermittently spiking voltage above 17 while it was apparently failing. IIRC they had other symptoms at the same time though.

Maybe consider keeping an eye on the in-cluster voltmeter. Or if you burn out more bulbs do some more precise testing.

Glad you got lighting back though.

That is good to know that I might have a voltage problem. I'll keep that in mind if bulbs keep blowing.

 

[LX Cruiser]

That is good to know that I might have a voltage problem. I'll keep that in mind if bulbs keep blowing.

Keep an eye on that voltage meter. Dash would go haywire for a couple seconds, lights would swell brighter, and bulbs would burn out. High and low beams. All without tripping a single fuse. I caught it in the act: