Fog Lights no power - solved, wrong multi-function switch installed

Inspection failed on 2003 tundra for fog lights out. Mechanic said he tested and got no power at the lights.

He gave me a print out of the circuit and a few other small things to fix, we both thought it was a fuse or relay. Especially since it just had a bad alternator and tensioner replaced.

well fuses look good and new relay didnt change anything.

what next? I have a meter, but none of those back probes or other fancy pants tools.

fogs are supposed to come on with low beams, no switch in the cabin

me monkey brain no like electrons oo oo aa aa

 

Are the fog lights on the stalk, or in the dash for your '03?

Did you install LED headlights or any running lights in LED? (and if "yes", did you install a resistor?)

 

What shifty said; also, check your manual (it's in the megathread stickied/permanently linked at the top of the main page) to make sure you're turning them on correctly.

 

I can't imagine your '03 is any different than mine, so you most certainly have a switch. It is on the turn signal stalk, inboard of the of the headlight switch. They are both rotational. Rotate toward dash for on, rotate to you for off.

 

My 2000 has the switch on the left lower dash panel. How can fog lights be an inspection item? Not every Tundra had them.

 

A lot of states follow the rule of thumb, "if light is installed, it must function".

Like in TX, it's true of the brake light on your cap. Apparently in NH, if it has fogs, they must light up.

 

In my world we could just disconnect it, label it INOP, log it in the maintenance logs, and be done with it. It is not required for flight. Hard to believe state rules are more strict than the FAA.

 

My stalk only has a two stage rotational switch at the very end
1) click for parking lights
2) click for low beams
Push stalk forward for high beams.

theres nothing else on it, no ring to rotate like ive seen in other cars. I called him back thinking PO installed a bumper with fog lights but no way to turn them on. Mechanic told me they’re automatic with low beams. Circuit print out shows power to relay taps off low beams *shrug*

everything is stock afaik. Im realizing i never checked if the bulbs were blown, so I’ll check that


Tbh i didnt realize this truck had fogs until he failed it lol.

 

Heres what ive got. checked bulbs and they seem old, but ok. No obvious breaks.

Lost my amp meters so couldnt test for power




does anyone know what that red light is for? Seems like an aftermarket something

 

Ill see if this is possible. I’m in NH, they seem to be pretty strict about things here

 

spoke with Manual, he seems to be suggesting I check the Integration Relay next

edit: where is the Drive Side Junction Block? Sounds like it's in the dash and not under the hood?

 

TBH this was kind of tongue in cheek. This is how we continue to fly aircraft with inoperative items not critical to the mission.

 

I suspect the PO installed an aftermarket alarm system. When these systems get old, they can wreak havoc on electrical systems. Not sure if it's related to your current problem, but there could be some wiring f*ckery that was done. Especially if the fog lights were wired into the low beam circuit. I can't think of any vehicle that did not have it's own fog light switch. I think I'd start tracing wiring back from the fog lights and see where they end up. Could be a total PITA.

 

Yeah it should definitely have a separate switch and it should most likely be on the turn signal stalk. Maybe it's been replaced and the wrong unit was installed or maybe there is some wiring hackery somewhere.

 

Everything in the manual mentions them being auto w/ DRL, so I think i'm ok there, but I'll yield to experts here.
I don't disagree that it's funny though

Aftermarket alarm system is possible, there were some wires coming out the driverside column. Assumed it was a microphone that connects to the aftermarket radio

 

Have any pictures of the front end and maybe the wiring going into the fog lights? Just wanting to verify that everything looks original.

 

Ok, so definitely aftermarket alarm is installed.

One of two things is true: PO replaced the original stalk with one that didn’t have fog light control, or they installed bumper with fogs.

Since you have no good way to know which is true, and you have a blank where the fog switch normally is on the dash, left of the alarm LED, is this: All our trucks are prewired for fogs even if they don’t have them from factory, and the harness is usually plugged into the obacl of that blank. Get access to the back of the blank. Is there a harness there (also look around in case the person who installed alarm LED disco’d it by accident)?

If so, you need to install the OEM switch which is NLA but a couple forum members on here have one in CA and TX. @jerryallday i think is one, and @txagg may be another. If there is no harness there, I think your fogs were potentially wired to a stalk and you may need to replace the stalk.

Easy workaround to pass inspection is simple: Remove the fog light housings. If no fog lights exist, there’s nothing to be inop!

 

PS - @BluegrapeVr6 retrofitted OEM dogs in his truck I believe, and can maybe provide details on whether there’s a relay or something he had to add. If there is, you can also check if that relay exists on your truck, maybe as another confirmation that your truck should have the fogs.

 

This PO is starting to get me PO'd XD

Well I've got an appt next friday for the mechanic to sort this out. He said doing electronics was his favorite so I'll let him have fun with this mystery
Here's hoping whatever solution he'll accept is cheap.

 

Thanks @ shifty. Check your build date. Your 03 was likely built in 2002. I am at work, but if you want to test theory about lowbeams, unplug foglight harness and check for power when you turn low beams on. Most likely you need a switch ( wiring already there) and a oem foglight relay ( spot for it already there) , I found oem switch for about $15?

 

I'd be curious if @woodamsc has the relay you're pointing at installed.

If so, and the fog lights are plugged in, behind the bumper, and he has the wiring pigtail shown, after popping off that panel, then all he should need is the dash switch and he's back in business.

 

Option 2, take the fog lights out.

 

Correct. Any old switch will work. Just need relay , switch, housings , and bulbs. All the connectors are pre- tucked back their for you.

 

Vehicle inspections are taxes, nothing more.

Although my state has that same tax, I happen to know a guy.

Literally how it goes: you pull in, walk into this office, tell him the mileage, he puts the sticker on, you pay him the tax. That's it.

My ABS has been out four years now. Dealership wouldn't pass it, silly as it's not needed, normal brakes still work. Thankfully, I know that guy.

 

Ok I think we just settled it elsewhere @woodamsc. 2003 had fogs on the stalk? So if there are wires behind that blank, it will probably be for the rear slider window (but the EWD would allow you to confirm that via wire colors)

I believe the column wiring should be pre wired for a fog light stalk and upgrade should be plug and play. I just couldn’t remember the year cutoff for when it moved from dash to stalk.

 

I've got an 03 SR5 and can confirm the fog lights are on the stalk. Dash is heated mirrors, blank, dimmer and alarm.

 

Can confirm definitely YES.

 

thanks for all the info!
I'm not knowledgable for electronics/relays and the likes.
In the fuse box I have Denso 6912 relays in the same spots @BluegrapeVr6 showed.
Fog lights have wires plugged into them at the back under the bumper. Lost my multi-meter so can't test for power.

Gonna take all this info to the mechanic and let him figure the cheapest way out of this is. Totally fine with losing the fogs, maybe a new stalk is cheaper?

Honestly just worried I'm walking into a big mess of who knows what the PO did

 

Removing the fog light housings is free.99

 

Yeah that's my #1 choice if mech is okay with it. I never found fog lights to really help with anything...