XM location in Trailblazer

The Wiring Harness and connector wouldn't be there! There should be a free port in the Back of the Radio, probably a 12 pin port. You would have to get the Wiring harness to plug the XM Unit into the Radio and any brackets to mount the XM Unit. I sure hope you can get your Radio Reprogrammed, because many many people have been trying to get it done at the dealer, and there's pretty strict about it. Seems strange and I haven't heard of anyone YET being able to get it done. You should be able to Order everything you need from the dealer Except the XM Module it's self. I don't know if Chevy has switched over to the Single Lead antennas yet or if they are still the dual lead antenna's. Look on the XM Module. If it's dual you'll need to get a adapter to covert from single lead Micro antenna to the Dual lead to plug into the XM Module. Or you can even get a stock Chevy XM Antenna and drill a hole through your roof.

No, on lots of issues....

I found the install location. Went to the dealer who gave me a diagram. Finally the location based on that pretty weak drawing. Seems to be under the glovebox. Theres 2 connectors down there that dont plug into anything. Neither fit, but I'm checking in the AM to see if theres an intermediate harness. One has 3 wires and a bare ground, bet anything thats the one.

there are no open ports on the radio. when they talk about opening a port, they mean in the radio itself.

I've ordered, cuz i'll need it anyway, the helm manual so I can figure it all out. dealer still says he will reprogram the XM, just as if it was one that got scrambled and had to be redone. the only thing that might bite me is if they have to get a license code from GM or something and they refuse because it wasnt on the invoice. i doubt thats the case tho. with this amount of work, i can understand why no dealers do it. so much easier to put in a $75 FM modulated POS and charge $400.....

and the antenna connectors are a bit different, gotta get the dealer better info on that. the one I have will work, but I am going to see if I can get another endcap....

anyone else have any more helpful info?