Fog light switch only turns on brights ??

2000 SR5 4x4 4.7.
>> I installed OEM fog lights and connected them to the existing harness located behind the front bumper.

>> I installed a fog relay in the engine bay fuse box and a 20 amp fuse in that same box.

>> I installed an OEM fog light switch in the dash and conected it to the existing the wire clip behind one of the blanks.

Problem: when the headlights are on and I press the fog light switch, the brights light up and the fogs remain off ???

Does anyone have any insight into this?
(Thanks for reading)

 

Do you have LED headlights installed?

 

That’s wild. What happens when you pull the stick back for high beams?

 

Yes. I have LED headlights installed.

 

My high beam switches a push button switch in my instrument panel. Brights go on and off when my low beams are on.

 

Add a resistor to the circuit...

https://www.superbrightleds.com/catalogsearch/result/?q=resistor

 

Sounds like one potential cause could also be using the wrong relay? I don't know for sure, but I say that because it sounds like when you throw the switch, it's activating the wrong circuit. Where did you get the relay, and did you get the correct type/configuration?

However, like the guys above said, we've seen all kinds of stupid shit when people have LED lights installed up front, it's documented in the megathread, but I'm not 100% sold that's what's happening here (could be, though, and it's something you should've been aware of before upgrading to LED)

@BluegrapeVr6 what relay did you use for your setup?

 

The 2000s are not wired the same as the later models and I’ve not heard of anyone with an early Tundra 00-03 or so having any issues with LED lights. I’m with @shifty` , check the relay wiring.

 

Yeah, I don't think people understand, there are multiple relay configurations. Just because the prong count/pattern match your receptacle doesn't mean it'll work for that specific application. Some relays are different in type/function but share same footprint/layout.

We've had people on here get generics from the LAPS for the fuel relay and starter relay circuits, only to find they won't work. Likewise, I've seen one person recently whose relay wasn't firing because of the circuit type it was used in.

I've be confirming the relay, since ... if OP really did use the OEM switch, and used the OEM plug, the main way the circuit could be misfiring would be if the wrong relay was installed in the circuit, so when the relay is triggered, it's toggling another circuit. But if the load on the circuit was low ... I suppose it could be the LEDs?

Fastest way to find out would be temporarily reinstalling some old halogens. And I'm also curious if OP is using LED fogs too, since that could be compounding things.

 

I agree, check that you have the correct relay first. I relay for the stalk switch is different from the push button switch. Also, I discovered the hard way doing mine that the fog lamp switch harness has other circuits running through it. You can isolate it being the switch if you run a jumper wire to close the fog lamp circuit and see if your issue still persists. The wiring diagram can be found HERE.

 

Is it a DRL or non-DRL truck?

 

I have the same issue. I have LED headlights with a load resistor and my factory fog lights are unplugged. With the headlights on if I press the fog light button it turns the brights on, and when I turn high beams on with the fog light button pressed nothing changes. After awhile of driving and pressing the fog light button a few times it stops doing it.

 

Non DRL truck. I have a Denso relay with the OEM Part number for that year. I have a pair of load resistors coming Monday and I’ll check back in next week and let y’all know how I fared.

 

Two resistors installed or only one? If only one, on which light, passenger or driver?

 

So the way non-DRL trucks are wired is what causes this. The fog light switch uses the high beam circuit to power the relay. This small amount of current isn't enough to even come close to lighting off the high beam filament of a halogen bulb. BUT, with an LED bulb that small amount of current is enough to turn it on. A resistor should fix you up.

 

I did need to put a resistor on my passenger light for high beam / dash light to work with LED headlights.

I also installed a new bumper with fog lights (std bulbs). My high beams come on with the fog lights. Haven't spent the time to troubleshoot - I figured I'd get LED bulbs for the fog lights first. Might try resistors (2 pack came from the original problem) or just rewire the lights.

 

I installed a resistor/anti flicker on each side sold for the LED bulbs I have
The headlights did not light up at all.

I removed the resistor, installed the original halogen lights and everything works as it should.
What this tells me is somewhat obvious: lights, relay, switch and power are all good.

I suspect I need different resistors. I ordered those last night.
To be continued….

 

Try just a resistor on the passenger side headlight. That's what a lot of people end up running.

 

Also, LEDs are polarity dependent

 

Return whatever load resistor you bought and buy this https://www.superbrightleds.com/mot...d-headlight-bulbs-h4-connection-load-resistor

Plug N play and all you need is one.

 

Something cool I found recently: Companies like Sylvania are producing non-polarity-specific LEDs now, so I think you may see this go away in the not so distant future.

 

I have a resistor on both bulbs, after reading a few posts I am going to remove the driver and see if that fixes it. I will also be adding led pods to the fog light switch. Will I need to put a resistor in line for those?

 

Bingo! Work perfectly. Thank you !

 

I all of a sudden had my fog lights fuse blow. I’m curious if the resistors I have in now can go bad and be the cause of this since nothing else has been changed since the led bulbs and resistors were installed before I bought the truck. I don’t see any other signs that would make me think I have a short anywhere. If I remove the resistor from the system I have the high beam issue.