IIRC the lock switches complete the ground circuit.
1997 Jeep Cherokee Ignition
Constant 12V+ Red/White Steering Column
Starter Yellow Low Current Ignition Switch Harness at Steering Column
Ignition Blue/Gray Ignition Switch Harness
Ignition 2 Black/Orange Ignition Switch Harness
Accessory Black/White Ignition Switch Harness
Tach Gray/White In Black Connector at PCM
Neutral Safety Wire Brown/Yellow (-) Switch on Transmission
Brake Switch White/Tan Brake Switch
Trunk Release Pink/Black (+) Driver's Kick Panel Rear Body Harness
Trunk Pin Tan/Black (-) BCM
Parking Lights Dark Blue/Red (+) Left Kick Panel or Light Switch
Head Lamp Tan/Black (+) Light Switch
Factory Disarm Purple/Yellow Driver's Kick Panel
Door Trigger Yellow (-) Light under Dash
Door Lock Orange/Purple (-) Driver's Door/Orange/Black Passenger's Door
Door Unlock Pink/Black (-) Driver's/Passenger's Doors
Horn Wire Black/Red (-) Steering Column
Windows Up LF=Light Blue, RF=Brown/White, LR=Black/White, RR=Gray/Black Windows Down LF=White, RF=Purple/White, LR=Red/Black, RR=Green/White
Jeep Cherokee Cruise Information
Constant 12V+ Red/White Steering Column or Use Hot Side of Brake
Switched 12V+ Blue/Gray Ignition Switch Harness
Ground Use Chassis Near Cruise Control Module
Hot Side of Brake n/a Brake Switch
Cold Side of Brake White/Tan Brake Switch
Tach Gray/White In Black Connector at PCM VSS Lead White/Orange PCM, Passenger's Firewall,32 Pin Connector
Notes: Vehicles with Manual Transmission require Clutch Switch. Some vehicles may require a speed signal generator and/or other parts/adapters not listed above. Rostra® Cruise module switch settings may differ if you use a speed signal generator or magnets and a pick up coil.