I just installed a n1 into my 2005 avalanche. I had to buy the coupling piece to go from the mini barb connector from the factory antanae to the one that goes to the brain unit, but no stations come in hardly. anone know if i have to have a signal booster or something? thanks.

what car? maybe power ant needs to be connected which is one of the blue wires on the back of the radio.

If you do, there should be talk about it in the harness adapter you purchased. Mine had a power wire that I had to hook up to the RMT wire (AUX) that turned on the amp for the antenna when the stereo was on.