Day Time Running Lights Relay

In the 1999 Chevrolet Tahoe, the Daytime Running Light (DRL) relay is indeed located under the dash.

I checked under the hood in the fuse/relay box and found a few relays, but not the DRL relay (they are all labeled). I did find a couple of relays under the dash, just above where your left foot sits. One was the exact same as I purchased (a 5 prong relay, about an inch square). I replaced that relay, but the DRL still don't work. Any more suggestions?

HiYes on your year it is left convenience center so the one you replaced was DRL relay.
Test light to terminal G5 a Purple wire see if voltage is there. This is what pulls relay in from the DRL module also on left side dash. If no voltage then module is not functioning. Also is DRL indicator light on?

Yes, the green light is on, on my dash board. I will check the purple wire later this morning. Thanks.

I'm not sure what or where terminal G5 is. I do have a purple wire plugged into the convenience center. I did use a volt meter and tested for voltage between the purple wire and ground. No voltage. Is there more than 1 DRL relay or do I have other problems?

Make sure beam indicator is on low beam.
The five trem. to relay hear is what you should read
Pink 12v
Yellow 12v
Purple 12v
Light green/Tan ground
Tan 12v
Do you hear relay click when placed into term?
Also on left side there is the DRL control module has about 11 wires to it this maybe the fault.
Let me know what you get at relay.