Cruise connector (and power trunk release if equipped) comes from the IGN3 circuit plug on the fusebox. It gets its power from the A/C 25A fuse. If you're A/C and heater and junk work, then that likely won't be a fuse issue. Feeds the blue wire to the switch. If you're getting power there, the fuse is good. If the cruise switch is ON, then you should be getting 12v out of the green wire which goes to the brake switch, which turns into a gray wire where the switch plug attaches. Another gray wire taps off of that and powers up the cruise module at pin input A. Out of the brake switch it's a brown/white stripe wire to the cruise module to pin input G. With the brake off, you should be getting 12v out of the brown/white stripe wire too. If not, the switch could be misadjusted or faulty.
On the servo, disconnec the plug, measure ohms resistance across pins E and C, and A and C. Those should be 30-50 ohms each. Across terminal B and D, you should have between 15-50 ohms. Anything outside of that, then your solenoids inside the servo are probably hosed.
Do you have an electrical service manual? That will give you some insight on the cruise control.