Here's the problem:

I installed a Terk XMCommander on a '82 SD with original Becker head unit.
The XM kit has an antenna splitter that interrupts the radio antenna to
allow a FM feed from the XM receiver into the radio. However, when the XM
unit is hooked up, I get great XM and FM but no AM--just static. To problem
solve, I unplugged the power cord to the XM receiver and AM works. I can
unplug the FM out feed from the XM receiver and AM works. Why do I just get
static when the XM receiver is integrated into the sound system? Better yet,
how the hell can I fix it, Oh Wise Ones?