Daytime Running Lights

I have a 97 ext. cab 4x4 with the DRL. The other day I went to the store and they were working when I pulled up ('cuz I could see them in the windows of the store). I set the park brake (they go off when you set the park brake) left the truck running, went in, came out, and when I pulled the brake release, the lights didn't come back on, and havent worked since. I dont think its the switch on the brake pedal, 'cuz the brake light goes off, and the DRL light comes on. I checked the fuse and its good. The manual says there is a relay, and a module, but no clue where they are. Any ideas where these are, or what the problem could be???

It is more than likely your DRL diode. It looks like a heatsink it has fins. It is on the right side of your steering column about knee height. you need 10mm wrench and some pliers to take it out. You can fix the same one by cleaning the inside out and press the rest of it, then heat the diodes up with a torch or soldering gun and press the solder in to the diode with pliers. Don't press to hard or you will break a diode. Keep water on hand to cool the diodes. To much heat will blow them. Or just go buy a new one for $40 dollars. hope that helps you.