When I click on GUIDE the first time, it only turns the TRACK and HEIGHT
buttons OFF, the rest of the AP works fine. Yes, I can still manually control it if I want, as long at the Mode Selector Switch is set to VOR 1/ILS 1, or VOR2/ILS2 (depending on which of those is tuned to the ILS frequency), it will track the ILS, and follow the Glide Slope all the way to the runway threshold.

I just have make sure I manage the C-130's speed when lowing the Landing Gear and increasing the Flaps, for it to work correctly for me.