You could be right about the power antenna. The one wire from the harness that I didn't connect was marked as power antenna on the diagram on my radio. But it came straight from the connector, no separate plug and it was grey. But my radio was from a Laredo. Could be that one of the base model radios had a separate plug for power antenna.
Doesn't matter to me, though. Don't have a power antenna on the MJ, and I swapped the XJ one to fixed long ago. Anyhow, I got everything hooked up and it works great. Thanks a bunch.
Also, I pulled the bezel off my XJ. Also threw in a clock, fog light switch and some other goodies.