Hopefully you guys can help with this problem that has me pulling my hair out! A bit of background first:

3 or 4 years ago the headlights on my 2004 TJ Unlimited would not turn off. It was suggested I remove the daytime running light module to see if it was the culprit. The DRL module was indeed the problem, and since all the other lights worked fine without it I just left the DRL module unhooked rather than spend 100 bucks on a new module. I have just sold my jeep, and in order to get it certified I need to get the DRLs working again.

So I bought another DRL module today. Plugged it in, no DRLs. Exchanged it for another DRL module. Still no daytime running lights! I checked the connections, fuses, checked the parking brake micro switch, tried unhooking the battery for half hour to reset the computer. Still no DRLs! Yet all the other lights continue to work just fine.

Am I forgetting something? The wiring appears to be in good shape overall, and my jeep has never been in water or even gotten muddy.
Hopefully someone else has encountered this problem before; it must be common because I see lots of jeep TJs without working DRLs around here.

Thanks for your advice!