Yesterday morning, I noticed that my DRL's didn't come on when I started my rig and went to work. So, I tried turning on the headlights and no dice on low beam, but the high beams work just fine. The high beam indicator in the dash works just fine and goes off when low beams are selected.

Last night, I checked all of the low beam and DRL fuses and they all check out just fine. I have a hard time believing that both low beam filaments could've gone out at the same time, but who knows. Any thoughts on what else I can check myself before I take her to the dealer?

 

Check if you have power to the lights. The low beam wires are green/white on the left and blue on the right. With the lights switched on low beam check for +12V on those wires. If you do have power then the bulbs are probably gone. It seems to be common on 4Runners when one bulb goes the same one on the other side goes soon after.
I have the wiring diagrams for a 2002 in pdf format, if you want a copy send me an email address.

 

I will check on the power situation tonight. Any other thoughts on what it could be?

 

Looking at the wiring diagram if it's not the bulbs it could be one of the DRL relays. I don't know how you would test those other than trying a new one. Do you know anyone with an 01 or 02 4Runner you could borrow the relay from to try it.

I'd let you try mine but it's a bit far away

 

Last night, I got my handy multi-meter out and did some voltage test on the DRL, low beam and high beam wires in the headlight harness. I had good voltage on all of them, so I pulled one bulb and the low beam filament was gone...same on the other side. Ran to the parts store, got a pair of bulbs and now I'm back in business! Thanks for your help eric!