AUTA 6000 Antenna Overload Unit Bad?

[punkinfair]

has anyone seen a how-to on testing the overload unit inside the AUTA 6000 EL? the antenna on our '87 300TD just died suddenly and it seems the overload unit is bad. the antenna has worked perfectly for years, i've changed the mast a few times over the years and i've always tried to keep the mast clean with those hirschmann wipes. but now the antenna has failed and for sure there is no power to the red and green wires that are the outputs to the motor from the overload unit.

it's probably a waste of time to try to test the unit, but if i knew how to do it i might try. wrecker parts for this kind of car are not too easy to find locally, there aren't many yards around here with 124's.