Low and high beams not working. Fuses and bulbs are ok.

Hi there everyone i have 06 toyota tundra sr5 and my low beams havent been working for a wile now and now yesterday my high beams aint working either i checked fuses and bulbs are just fine .. my parking lighta work tail lights and blinkers all that work any ideas ??

 

Tried to find a quick wiring diagram for a 2006, all I found was a 2002. Assuming your wiring is similar, your headlights are inline with 2 relays (Dimmer and H+LP) before the actual lamps, and a relay and load resistor after the lamps. Given what you described and the schematic I'm looking at, I'd say it is probably the Dimmer Relay (fouled). Just a guess. Try giving both those relays a good smack with the handle of a screwdriver while your have your lights set to on and see if anything happens.

If that doesn't help, I might dig into Rainman's massive pile of schematics later. Hopefully a 1st gen somebody will be able to help before that.

 

Are you 100% certain the bulbs are good? If so, then I would recommend getting a 12v light or meter and start chasing the wires from the headlights back to the point to where you get power. Once you do that then you've isolated where the problem area is. Logic is your friend here. Keep it simple.

 

Wiring diagram can be found in the 2006 Tundra Factory Service manual PDF in the link below

https://drive.google.com/file/d/0B-...WjA/view?resourcekey=0-lv7xW9_5TKqpbWKbBzVP0Q

 

Hah, thx, but I meant a quick search, that pdf is almost 5000 pages non-indexed. Rainman has schematics for all the Tundies, I was just hopin to come across something quicker. Took a random guess and I landed near the right page lol (3800) area.

 

Ok, so on page 3807 and 3811. From what I can see and what you described, I'd say it is the c15 combination switch (whatever controls your off/drive/headlights). So, before you do anything drastic, hotwire your headlight bulbs to make sure they are actually good. Also, check your battery and alternator voltage. Low voltage can cause excessive fouling/low voltage welding in switches and relays.

Does your truck have DRL?
In fact, before I go any farther, why don't you tell us exactly which truck (AC, DC) engine and light options you have so I can be sure I get on the right schematic.

 

@Gravy to the rescue . . . very cool.

 

Well, I'm willing to try to help, but doesn't look like this guy's been on since he posted...

 

There was a guy on here that I Dm'd about an LED lightbar installation behind the lower grill/grate on his DC . . .looked super clean and was really bright. He offered to do the install for free if I bought everything and went to his pad. I thought that was super cool. I didn't take him up on it, only because I thought the light bar might block some of the radiator and restrict air flow . . . I travel through the desert a few times a year, so I was a bit sketched. Cool gesture through.

 

posting here on the off chance people in here might still see it.

i have a similar problem. my criteria are a bit more complicated but similar issue.

Background:
-2005 access cab sr5 4.7
-G5 HID retrofit. Installed 2019, has worked flawlessly
-Have G4 resistor for high beam indicator and fog logic fix, has worked great

Issue:
-low / high headlights and fogs do not work
-Added DD SS3 LED fog lights last month with plug and play harness. Aimed them, worked great with headlights while aiming. Drove around to test, all good.
-Next day, fogs wouldnt work when truck started. Restarted truck, they came back on with headlights. Restarted third time, headlights (both high / low) wouldn’t turn on but fogs worked. Restart after that neither fogs or high/lows work - current state, multiple starts.

-Marker lights and driving lights still work. High / lows / fogs wont work at all.
-no flicker or any signs prior, nothing changes when jiggling wiring etc.
-reinstalled OEM fog lights, both headlights and fogs still dont work.
-checked fuses in hood, all good

Anyone have thoughts? Wish OP had posted his progress / fix!

 

I would consider the physical switch as your problem and contemplate replacing it, maybe with a junkyard unit for a cheap test.

There's also reasonable probability you have a relay that finally shit the bed.

 

thank you! ill start with relays and then look into the stalk switch. do you think the fact the driving / marker lights work when light switch is turned on would factor that out at all? sorry if that's a dumb question.

 

Did you wire the new fogs into the trucks headlight wiring? Or separately? If they are wired into the trucks headlight wiring/ fog light system, they are likely the problem. The system is voltage dependent, and your setup could now be on the edge of its operation, making it intermittent. Unhook the fogs and see if the issue goes away. Also, how’s your batteries health?

 

I don't think it's a dumb question at all.

In my 2006, I'm also running SS3 fogs (FoxBeam kit) up front with plug-and-play adapters. I run BraveWAY/COlight LED H4 mini projectors in my stock housings, Sylvania LED for the parking (teardrop) light, halogen for the turn signals. I have a Diode Dynamics SmartFlash, and I'm not using any restistors.

Going from memory when I finished my SS3 install a few weeks back, this is how my system operates with that configuration:

• My headlights are on all the time (b/c "DRL", I think),
• That's potentially true even when I'm set to parking/turn only (I think; it may be setting to the parking/turn signals is the only way to get my headlights off)
• Fogs will only work with headlights ON, I can't run fog + park only
• Fogs turn off when high beams are active

The only other place I have LED installed is in my 3rd brake light (HMSL). I'm intentially not going all-LED.

Anyway, not sure if it helps or not, but ...

 

thanks. using plug and play adapters to OEM fog wiring. OEM fogs are back in - everything still not working. Same when just fully unplugged. Battery is new and part of a dual setup. Both healthy.

 

Yeah, I'd be dummy checking at this point.

Ensure high beams are actually off, first and foremost. And DO NOT rely on the dash light to tell you that, bounce them off/on once.

If they are, I guess I'd be checking relays. But If I had a dollar in my pocket for every time a fellow 1st gen'er had their foglights stop working (for guys using the stalk) and it turned out to be the switch, I'd have enough to buy a cheap lunch at Wendy's. Still, relays.

 

Thanks every bit is helpful honestly, been researching this for weeks now.

Running the Foxbeam kit as well! No LED anywhere except for the SS3's. HID retrofit kit with the resistor that i have run for 5+ years now. Grounds seem fine, wires pass the visual check though I guess i could recheck them and freshen up the ground contacts. Weird that it did totally different things the first 5 times i started the truck and then finally just stopped working entirely.

 

this is super helpful.

 

I wish I knew the relay setup on the light circuit in these trucks, but your commentary on that is what immediately made me consider relays.

Main purpose of a relay, in case you're not super familiar, super dumbed down version here ...

There's effectively a small "switch" (best fitting term I can think of) inside of the relay which acts similar to one of those train track switches, and when something instructs the switch to switch tracks, it moves the circuit to a new path.

It's able to make the track switch using a magnetic coil. When that coil is either fed power+ground, BZZT! The circuit switches. Typical example of a common switching relay I used all the time bitd is here, a single pole relay or SPDT (1 power post, able to switch between 2 circuits). Basically, the coil is that spring thingy between A and B. If I add power flow to A&B line, it will energize/magnetize that little coil and the "T" arm will jump over to post position 1, lighting up power to fan 1, killing fan 2. If I remove current from A&B circuit, the no more magnetic field, and the arm kills fan 1 and starts fan 2. Simple, right?

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Now, there are multi-pole relays out there (more than 2 selections), and you can string together relays any way you want to do all kinds of stuff, even using relays to control other relays. I'm not saying it's "right", but you can. They also make dual pole relays (DPDT) and beyond. I'm not an EE, and I've never needed more than an SPDT so who the hell knows what's out there.

Anyway, when you flip to a new selection on your stalk, THAT is what (should be?) causing that A&B circuit to energize and activate to switch +/- (power/ground) to feed whatever it should be turning on. When you say you got 3 different behaviors, one with each startup, thinking about that ... if they used a DPDT (dual pole, dual throw) for example, and the relay was dying, and it threw on both poles as expected the first time, but the coil was weak/dying, so the next time, it was only powerful enough to throw one coil, then the third time, the coil failed fully and couldn't throw shit, and now broken so it stayed that way, well ...

Good example of that scenario, picture this. Same as the SPDT above, with one magnetic coil to the side. That one coil causes both 1&2 + 3&4 switch to energize and jump between. Say the coil is failing and it can only cause the closer pole to jump. Then the coil fails, now it can't make anything jump. This is what triggered in my brain with your description up there. Hopefully this shit makes sense to you, I have a tough time explaining it. But this is why I'm saying, "We've seen bad switch cause similarly stupid shit ... but check the relays"

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you sir, and folks like yourself, are why these forums are still often much more useful than the Facebook groups. appreciate you taking the time here. heading out the door to go see what i can deduce using some of this info. i will report back.