Some 2007-2008 Mustang vehicles may exhibit un-commanded perimeter lighting feature (head lamps / park lamps / side marker lamps) due to water induced short to ground in the door disarm switch.
Follow the Service Procedure steps to correct the condition.
If the vehicle exhibits intermittent un-commanded perimeter lighting feature (head lamps / park lamps / side marker lamps) then replace the door disarm switch.
Remove the left hand (LH) front door trim panel. For additional information, refer to Workshop Manual (WSM), Section 501-5.
Position the watershield aside.
Disconnect the door disarm switch wiring harness retainer from the post on the LH door latch.
If equipped, remove the rear glass run.
Remove the E-clip.
Remove the lock cylinder actuator pawl.
Remove the door disarm switch.
Before installing the switch:
Verify that the door disarm switch mark is positioned toward the harness side of the switch. (Figure 1)
Figure 1 - Article 08-9-2
Apply Motorcraft® Silicone Brake Caliper Grease and Dielectric Compound liberally to the switch and lock cylinder mating surfaces. (Figure 2)
Figure 2 - Article 08-9-2
E-clip must be positioned with the concave side towards the lock cylinder (upside down U) to ensure the proper tension is applied toward connection. (Figure 3)
Figure 3 - Article 08-9-2
FAILURE TO PERFORM STEPS IN FIGURES 1-3 MAY RESULT IN REPEAT INTERMITTENT COMPLAINTS.
If equipped, install the rear glass run. Torque the screw to 80 lb-in (9 N-m). Torque nut to 89 lb-in (10 N-m).
Connect the door disarm switch wiring harness retainer to the post on the LH door latch.
Position the watershield back into place.
Install the LH front door trim panel. For additional information, refer to WSM, Section 501-5.
Door Disarm Switch
Motorcraft® Silicone Brake Caliper Grease and Dielectric Compound
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
2007-2008 Mustang: Replace Door Disarm Switch. Time Includes Removal of The Door trim panel and If Equipped The Rear Glass Run (Do Not Use With 23943A, 21990A)