Had the same problem and still do... BUT I think I know why it happend to me. In the process of soldering on LED's in place of those stock A/C control board bulbs, the solder jumped the circuit and I'm pretty sure fried the board.
I installed a flat 5 LED strip behind it, wired to the same relay as the head lights. No dimmer controls, but at least i've got lights
All fuses have been checked, I'm just pretty sure I nuked the board.