2003 rear window shot out, antennas?????

So, last night while driving home someone shot out my rear window. I'm guessing it was a BB gun because it went pop as the glass cracked, there wasn't a gunshot noise like a bang.

Anyway, my 2003 custom does not have OnStar, although I think it was an option.

When I go to the glass shop to get it replaced, they ask if i had OnStar, I said no. I'm guessing some glass has OnStar antennas built in.

Then, I get called again and they ask me about OnStar again, becuase apparently the connectors aren't matching up.

So, I explained that the car is "OnStar ready" but it never had the option.

After that, I did some checking and found that the rear window has the "diversity antenna" for the AM/FM radio and rear defrost, but no mention of OnStar.

So, now I'm thinking that they botched the install, and either the radio antenna or the defrost won't be properly connected.

I don't care about OnStar, I won't be buying it, but I use my radio daily, and I'd like to be able to check and see if the antenna is properly connected and the defrost is connected. (of course now after the worst winter ever it's warm now)

Any tips or reference manuals to check the antenna and defrost connections?

I was in there on my 99 because the defroster quit working, it may be similar for 03. Pry off the side trim panels that covers the pillar between the top of the back seat and the roof. You should see a connector with wires plugged in to it. One side has both the defrost and antenna, the other side has just defrost. I found that the defrost connection generated so much heat, that over the years, the whole connector melted (solder too) and it lost the defrost connection.

Thanks for the info. So far, the radio still picks up those far away stations, but I haven't tested the defrost (too warm today).

Apparently the grid on the drivers side is OnStar, the grid on the passenger side is defrost, and the connector on the top drivers side is AM/FM radio.

You should be able to see the volts gage drop briefly and possibly a slight change in the engine rpm when the rear window defogger in turned on initially. They draw quite a bit of current, so you can check for operation regardless of outside ambient temperature.