GMC Repair: 99 gmc suburban drls, gmc suburban, daytime running lights

Question
My daytime running lights on my 99 GMC Suburban are not working. (combo drl/headlight) The light on the dash indicates that they are on.  The headlights are working fine.  I have checked the fuse, and it's ok.  Would this be a defective sensor that is under the dash? And if so, where exactly is it?
Thanks for the help!!

Answer
Hi
Sounds like the DRL Diode is your fault.
Yes it is located under the dash, just to the right (passenger side) of the steering column. It is shiny silver  and is "finned" like a heat sink for a CPU.
Be careful it is sharp and the bracket is also sharp.
I Hope this helps.
Good Luck
Pawl