Looking for hot fuse when lights on

Don't know if this is possible, but someone else is probably smarter than me.

I have the Auto Headlights. In the Auto setting, they switch from Daytime Running Lights to Low Beams as needed based on how light/dark it is outside.

Is there a fuse that is used when the headlights are on, but not when the daytime running lights are? This is the fusebox from under the dash. Going to look in the engine bay next as I understand there are fuses there as well.

 

Maybe I missed it, but what are you trying to do or what is the problem?

 

Not sure your answer, but have been thinking about this for my truck. I'm thinking tapping the 'tail' 7.5A. It has power when the tail lights are on (along with the headlights) but not DRLs...

 

I'm running interior floor accent lights that are only on when the headlights are on. I'll also be putting a switch in so that I can turn them off when I don't want them.

Below is the fuse/relay box in the engine compartment.

I'm thinking it's one of the ones on the lower left.
H-LP LO
H-LP LH-LO
H-LP RH-LO

 

Getting out the multimeter. Time to learn. Testing that TAIL fuse first. Thanks. I'll update later and change the thread title when I'm done installing.

 

I've used TAIL for this in the past. I'm just not sure how it'd work with the auto headlights, but I'd assume it would act the same.

 

OK, so TAIL is no good. In Auto, it is always on. It only loses power if I switch to DRL OFF on the selector.

However, I was kinda right in my above assumption. Both "H-LP LH-LO" and "H-LP RH-LO" work. I'm assuming they are the headlights.

Lo-Beams = 12V
DRL = Off
Auto = Off if DRL, On if Lo Beams being used.
DRL Off = Off

This should work perfectly. Now I have to run the wire from the engine bay fuse/relay box to the interior cab. What is the easiest route? Through the grommet in the firewall under the driver side dash or under the carpet just behind the driver side seat? I'm thinking the later as I also need to run LED bed lights with a switch inside. Thoughts?

 

I always run stuff through the driverside firewall. I'll wedge a flathead screw driver through the side of it to make an opening, then fish the wire through. I usually tape the wire to a wire coat hanger first if I have one.

 

Interesting. If TAIL is always hot, what trips the tail lights on/off with the headlights then? I sure don't know...

 

With the Auto headlights, Daytime Running Lights are always on, unless the Lo/Hi Beams are on. Therefore, the taillights are always on no matter what. As far as I can tell.

 

But they're not. They're off until headlights turn on.

 

Am I misreading my selector?

Hi-Beams (if selector pushed away) (Blue Indicator light)(Tail and Tag lights on)
Lo-Beams (top most)(Tail and Tag lights on)
DRL (Tail and Tag lights on)
Auto (Switches from DRL/Lo)(If Lo-Beam being use, can see Yellow Indicator Light)(Tail and Tag lights on)
DRL Off (All off)(Tail and Tag lights off)

Also, DRL are the "L" shaped LED lights, lo-beam is the outer most bulb, and hi-beam is the inner most bulb.

Correct me if I am wrong.

 

Here's mine

headlights : heads on / DRL on / tails on / markers on
parking lights : heads off / DRL on / tails on / markers on
auto : heads / tails / markers are all auto & DRL on
DRL off : all lights off

Looking back, that's the same as you. I wonder if you were reading TAIL as hot because your auto lights were on, but they'd be off in brighter ambient light?

 

Ah, miscommunication in my original post maybe. I wanted to be able to leave my selector in Auto, but only want the power to be available when it switches to headlights, not DRL. As in, I don't plan on switching off of Auto. So far, I like the feature and I don't have to think about my lights.

 

This is so simple. Just hook your interior lights to a fuse that is "hot" when the ignition is turned on to light the lights. The lights can be on all the time if the engine is running. You will never know they are on until it gets dark outside so problem solved!

 

When you say wedge, do you pierce the grommet/rubber at all? Seems pretty tight around the wire bundle. I can see the electrical tape from the interior side, but it would be a hard unwrap/wrap.

Also, do you remove anything in order to get a better work area around it or just work in a cramped environment?

 

No, I squeeze it in between the firewall edge and the grommet itself. I don't remove anything either, which is where the coat hanger comes in handy. Bear in mind this is on my second gen, so it may be a little different on your truck.

 

I don't want them on if they don't need to be. Just trying to extend the life of them some. If it takes a little more thought and elbow grease on the install, I can live with that.

 

Ah, edge of the grommet was easy to move, but was unsure how safe/waterproof that might be. Guess I could silicone it after as well?

 

I've routed many a cables through there on both this truck and my other Tacoma. I've never had any issues. Just use common sense and if it visibly looks like it may leak, take some precautions to fix that.