a55bruce

Check the DRL-FOG fuse again. Is the DRL relay working? You should hear it click when you unplug it while the DRL's are supposed to be ON. Look for bad connections/ terminals around the relay. Can you measure the voltages at the relay socket, report back which terminals have 12V.

justimagination

Thanks Bruce for the reply. Seems to me that I saw a Y-tube video sometime ago and there were two (2) black square relays on the very bottom of the fuse panel on the firewall. I believe the man was checking for 12v to determine if the controller on the right side of column was bad. Does that sound right to you ?
David g.

a55bruce

Sorry Dave I don't know where your DRL relay is located. You should try swapping the DRL relay with another relay. (duh...palm to forehead slap)
If that doesn't fix the problem, get the test light or voltmeter and check the relay socket.
You should find 12V on 3 terminals, this will help us find which circuit is not working....
12V from DRL-FOG fuse
12V from GAUGES fuse (key- RUN position)
12V from the LOW beam switch (LOW Beam Lights ON)

justimagination

Bruce, I found the video again on YouTube, and the culprit that is more than likely bad is called a "DIODE" a small square box located close to the column, that has the final connection, which comes from the relay, and continues to the DRL's. When I get time, I will take it out and replace it. I believe that's what s keeping the DRL's from working.
David g.

a55bruce

Yes, the diode may be the problem, but before you start throwing parts at it, I'd do a relay swap (easy/no cost).

justimagination

Bruce, I checked the fuse box again and there is only one (1) RELAY IN THE BOTTOM, the other one is for the door chime. I wondered if there were more relays, like under the hood in the fuse box, but none even though google showed a DRL circuit in there but mine does not have that design. It's just been to hot to mess with.
David g.

a55bruce

Dave,
Do you have a "convenience center" by the parking brake pedal?
http://ww2.justanswer.com/uploads/dt...020246_pic.gif
Check there for the DRL relay. Maybe it's just loose and needs pushed back into the socket. Try swapping the DRL relay with the Fog Lamp relay.
It's been too hot here too!
Stay cool.

justimagination

YES I do have one, I call it a small fuse panel. Item 3 (fog lamp relay) not equipped on my vehicle, it's empty. If it was there, I could just swap it with Item 4(drl relay) but that's not an option. I did remove the drl relay to check for any corrosion either on the relay blades or socket and all was clean. I'm going to check with my local salvage yard and get the Diode module and replace it. Since we started this conversation, I have checked other GM forums and it seems like 99% of DRL problems are related to the Diode module. They said they got a used (10.00) one, plugged it up and it worked perfect. I hope it works for me, I'm real picky about my Tahoe, stays in garage most of the time and I drive my Honda CRV. Thank's for hanging in with me, I think the end is near for my problem. Stay out of heat, drink plenty of water. For now,
David g.