what is this light and how do I turn it on?

[ypsetihw]

Pretty self explanatory - I'm new to playing with Tahoe and I was goofing around with the lights today and noticed something. There appears to be an extra bulb in the lower headlight housing next to the turn signal. It appears to have wiring and there is def a good bulb in there, but no matter what combo of lighting switches I hit, I can't make this thing turn on. What is this aux light for? How do I turn it on? See the pic . . .



---------- Post added at 12:48 AM ---------- Previous post was at 12:39 AM ----------

are these the DRLs?

sorry for such a dumb question, on my car the DRLs, highs and lows are all the same bulb . . .

---------- Post added at 01:18 AM ---------- Previous post was at 12:48 AM ----------

Wow ok so it is my DRL, but it doesn't seem to work right. I guess I'll check the bulbs and harness. Is there a relay for drls that could be at issue?

 

[ID_Escalade]

Yes those are the drls and they come on when you take it out of park.

 

[Eagle]

you have to be out of park AND with the P brake off IIRC. you'll need a mirror or a helper (or a garage door) to see if they come on. They are probably burned out, or someone pulled the fuse because they didn't like them.

 

[General Stalin]

You could just get on a flat surface and put it in neutral too, block the wheels for extra safety then you can look for yourself. Also I think DRLs are a real typical replacement part for these truck. No joke like over 50% of the GMT800 body style trucks I see (Tahoes or Silverados) all seem to have a DRL out.

 

[Narco]

i hate the drls...im gonna pull the fuse one of these days

 

[ypsetihw]

I was thinking, could we do a ghetto upper high 6/low 4 on the early tahoes by bridging the power to the low beams to the DRLs, so they stay on when the lights come on? Then if you did the normal high 4 mod, you would effectively have an "upper" high 6, Low, High and DRL

 

[blue70chevelle]

Just hit the unlock button on the key fob when it's dark out. The DRL and reverse lights should come on..

And I jumped it so the lows, highs, and DRL come on with the high. a different version of the 6high mod..

 

[ypsetihw]

And I jumped it so the lows, highs, and DRL come on with the high. a different version of the 6high mod..

yeah that's what I wanna do, how did you accomplish it?

 

[blue70chevelle]

Go into the tech section and look for the 4 high/6 high thread. That will guide you through the process. Instead of jumping the fog lights, when you pull the fuse cover, look for the relay that says DRL, and jump that one instead. They're all in the same area in the fuse box under the hood.

 

[ypsetihw]

Go into the tech section and look for the 4 high/6 high thread. That will guide you through the process. Instead of jumping the fog lights, when you pull the fuse cover, look for the relay that says DRL, and jump that one instead. They're all in the same area in the fuse box under the hood.

One step ahead of you - I already did the 4-hi, but I wanna do the 6-hi with DRLs not fogs . . . keep in mind I have an 01 and the DIY for jumping the relays for 6-hi won't work on my year

I've actually drawn up a logic table with the +/- circuits and current to each light based on many wiring diagrams and a little thought, here's what I've come up with so far for how the "SUPER EASY" 4-hi works on 01s, and then a draft of a potential bridge that would allow a "DRL hi 6" on my model year. Green cells have an active power and ground, meaning the light is on, yellow is either power or ground active, red is both power and ground switched off. Is this right?



If I am correct, the DRLs have a constant ground with switched power, while the Low and Highs have constant power (in the headlight ON, non-DRL state) with a switched ground. That's why providing a constant ground to the Low beams works for the 4-hi mod. If this is correct, you should be able to bridge the high-beam power to the DRL power (which has constant ground) to have the DRLs come on with the High beams. If you already did the 4-hi mod, then it would look like this for the 6-hi . . . would this work?