To troubleshoot, you should:
1. Consult your owner's manual: This is the best place to start. It should have a fuse diagram showing all the fuses and relays and what systems they protect. Look for fuses related to the PCM, body control module (BCM), or ignition circuits.
2. Check the Powertrain Control Module (PCM) fuses: This is the most likely culprit. The PCM controls many vehicle functions, including cruise control. A blown fuse here could disable cruise control.
3. Inspect all fuses: Even if the manual doesn't list a specific "cruise control" fuse, visually inspect *all* fuses in the fuse boxes (usually under the hood and inside the vehicle, often under the dashboard). Look for any that are blown (burned out or with a broken filament).
4. Check the relays: Relays are also electromechanical switches that can fail. Your owner's manual should show the location of relays, some of which might be related to the cruise control system's operation.
Important Note: If you are not comfortable working with electrical systems, it's best to take your Durango to a qualified mechanic. Incorrectly diagnosing and replacing fuses or relays can potentially cause further damage.
