First post. Forgive me if this information is available, but I just haven't found it. I'm hoping that someone has added this unit to their non-xm factory head.

I did read https://www.hummerforums.com/forum/s...ead.php?t=5916

1. My H3 did not come with XM. Are all of the 6 Disc factory units with the Band button XM compatible?

2. The OnStar antenna - does that double as the XM antenna? There's some talk about that antenna working with SIR-GM1.

3. I'm a bit confused as to where the power source would be. Is it the case that if the vehicle was previously wired for XM, then the power is already supplied, but otherwise tap into the cigarette lighter or something?

Many thanks!

 

Well I ordered the kit. I'll post the results soon.

 

Installation was a success. I will admit that I just had Best Buy do it. They charged me $19 and did a better job of routing the antenna than I could have. So in conclusion:

1. My H3 did not come with XM, but the SIR-GM1 still worked.
2. If you don't feel comfortable, or don't feel like doing it, get a quote from Best Buy or other installer.
3. In my case, the factory antenna would not work.