First of all I used search button but nothing came up. I just replaced my H/U with an aftermarket Pioneer unit. I got it installed at Best Buy. This morning I started the car and the A/C panel backlighting was on but as soon as I turned the lights on the A/C backlighting turned off. Last night everything was working fine.I am mechanically inclined so I did some diagnosis. The unit gets power , ground and backlighting signal. So the situation is that with the lights off the lcd panel which displays the time and vent settings is lit up but as soon as I turn on the lights to any position the lcd backlighting turns off and the buttons don't light up except for the emergency flasher button. If anyone has had the same problem and fixed it please let me know what the problem is.

i got the same problem, mine never worked

I have heard of a few lately with this issue, some happening out of nowhere. In your case I am going to say that pulled power or ground from the HVAC harness for some reason. Pull out the center console and check that harness for any HU connections. If there is one there, try unplugging the HU and seeing if the problem persists.

*When* did you get it installed at BB? If it's been within the last few days, take it back to them and tell them to double-check everything. Some BB install shops are REALLY good. Some are, well, let's just say that they're not. But it's a strange coincidence that it just stopped working after they pulled your dash apart.

OK so I swapped out the new HU for the stock unit and still nothing. This makes me think that the problem is not radio related but either a HVAC problem or it's a harness problem like engifineer said.

Maybe th HD now uses more power, so when the lights go ON, it takes the remaining power.

uhm... i don't think so....

they must've done something to the harness... wouldn't see how else... perhaps something is just loose?