Turn your headlights on and leave the button alone. They turn off automatically so not harm.

There may be an even EASIER way I am currently investigating. I have been talking with Asmara through email, he did this mod on his 4th gen 4Runner using the Toyota light sensor, but he actually had to replace his dimmer switch with the Limited's switch (which costs a lot). We may be able to use our current DRL dimmer switch like you said guamlet (according to the wiring diagrams), but using the Toyota sensor (around $100). If we our lucky, the harness may have the plug already for the sensor there, and it could be as simple as plug and play. That is best case scenario. Worst case, we may have to tap into the right pins on the main connector to the ECU, but I think there is definitely a solution.

I am probably going to pull my dash apart this weekend and check everything out. I have all the wiring diagrams (thanks nashman!) so this should be very doable.

I see two ways this mod can happen. An expensive and easy way with the stock sensor, or the cheap and harder way with 3rd party sensor and relays. Either way I plan on figuring out both or 1 at the least.

Guamlet, let's try to figure this out. I live close to DT Orlando, I'd be down to meet up and take apart some 4runners. Then maybe hit some trails.


I think some people just like the idea of DRL on instead of using the extra power of there headlights during the day. Also, your headlights will last longer if they shut off for the day of course. I know we can hit the switch manually, but the challenge is what I'm after ;) and because my 04' Blazer had this feature and now I'm on a mission.

A few updates on this mod for those of you that are interested.

I investigated the pin wiring, and it turns out, you can use your stock dimmer switch with DRL for the Auto mode, so no need to buy that part (which was expensive). All you need is to buy the sensor, which runs around $100, a connector, and some 24 awg wire and connector pins. The sensor wires will just need to be tapped into the Main Body ECU harness. I have been studying the wiring diagrams for days now so I am pretty confident this will work.

I ordered the parts I need, so hopefully I will have everything I need by next weekend so I can attempt the mod and let you guys know how it works.

I'll post some pictures when I finish it up.

Cool, hope it works out.

Please keep us informed on your progress...I will be returning home on a tour break to see my truck. I would love to do this mod if it works out.

Just want to send out an update for those following this mod.

As of today, I finally have all the parts to start the project. (sensor, connectors, terminals and wiring). I have already taken apart the dash several times (researching and another mod to hold me over while I waited for the parts) so it should be a relatively quick install now that I know what I need to remove and what pins I need to tap into. Also, I want to mention, in this mod, there is no need to cut any wires at all! So it will be a very factory-like installation.

I am going to put together a very thorough write up with pictures like Antman always does so that this will be possible for others. In an ideal world, I could potentially do this on Sunday, but if not, look forward to seeing it sometime next week.

See you on the otherside

Cheers, Nick

Thanks for the Teaser Nick, are you in Marketing? LOL. Looking forward to your write up.

In all my past cars with auto-on, I've never used it. The main reason for this is that I don't want to shorten the lifespan of the bulbs/filaments/ballasts.

Any update ndlaham?????

Im gonna attempt this same mod here soon....

Yeah, I have everything wired up and ready to go. Sensor is in (has been for weeks) and wiring is to the ECU. I hit a road block though and have been trying to resolve. I cannot source the correct terminals for the ECU. I have the internal Tyco part numbers but they are nearly impossible to get.

Currently I am looking into other ways to connect the wires to the right pins without getting the terminals. But if anyone has a crazy source of getting terminals let me know. I called Tyco Electronics, Toyota, DigiKey, Mouser and everyone you can think of.

But I will have a crappy work around just to show the concept works this week. I'll post a little video later on.

Not EVERY time - I had the lights stay on and drain the battery even though I double-beeped the remote. I like AAA! They had someone there in 20 minutes.

Dan K.

This is more than likely changed by the time of day in the radio (ie CLOCK) rather than by a photocell (light or dark outside). My Garmin does this based on time of day.

There are also a few other reasons to have the feature. I personally don't think it is neccesary to keep main lights on all day, it will ruin the life of them and I think it looks weird to have them on during the day. I think just the DRLs on during the day look really cool.

Also, it actually says in the manual it can improve fuel efficiency, by how much I'm not sure. It would be cool to test this. I'm too lazy, maybe Mythbusters will do it.

I actually found out how this was happning. It is direclty link to the headlights switch which makes sense. When I was on DRL, it was showing the day mode. When I switch to full headlights, it will switch to a darker screen for night mode. This is so obvious in retrospect.

This is actually another good reason to have auto-headlights, is that when the lights switch from DRL to headlights, it will also adjust your dash dimmer and nav screen mode.

So the mod isn't working right now. It could be due to a couple things but it's going to take me awhile to figure it out.

I'm pretty sure the wiring theory is fine. It could be that the stalk switch may not be connected to the ECU for auto (I have to check the junction box). If it isn't I'll have to wire it in.

Also, could be my workaround since I don't have the correct terminals. I may have a bad connection somewhere in the ECU. I also, I may have pinched a wire as I accidentally slammed the door on the wires, but it was shrink wrapped so I can't tell. I'll keep working on it and redo the wires, but as of now, not looking great. May be several weeks before I have time to find the fix.

Sorry guys, I won't give up though.

Nick