98 GMC Sierra head unit

I just installed a hi/lo RFconverter on my factory head unit in my 98 GMC Sierra truck.  At the back of the head unit I cut the front speaker wires.  I ran the output of the head unit to my RF converter and I now have the front speakers running off an amp.  Everything is working great EXCEPT the lights for my number 3 and 6 on my head unit no longer work.  Is there a wire on the back of the head unit that could have came loose that would only affect these two buttons?    I am not sure what I may have done, but they worked fine before I did this work.  Any ideas/suggestions would be greatly appreciated.bcuz

That's a new one on me... it could simply be one of those unhappy accidents that happen sometimes...

the bulbs that gm tends to use for dash lights and instrument lighting tends to blow out fairly easily from any form of impact or vibration. i wouldn't be surprised if that was the source of your problem here. the illumination wiring at the back of the h/u should affect all the lighting on it, not just 2 of the buttons. you can consider taking apart the h/u to get at the bulbs, but it requires a fair amount of patience.