Diagnostic Aids
Troubleshooting wiring harness and connector hidden concernsThe following illustrations are known examples of wiring harness, splices and connectors that will create intermittent electrical concerns. The concerns are hidden and can only be discovered by a physical evaluation as shown in each illustration.
Non Safety Restraint System Repairs
Several components, such as the PCM and ABS modules, may utilize gold plated terminals in their connections to the wiring harness. Replace all gold plated terminals with either a gold plated terminal or a "universal" service kit with a plating of silver or tin with grease already applied.
IMPORTANT NOTICE REGARDING SAFETY RESTRAINT SYSTEMS:
Restraint system terminals must not be removed or repaired
Restraint terminals are not be repaired/replaced with individual pins/terminals.
Ford no longer requires replacement of the affected harness if a restraint connector or terminal requires service. wiring Pigtail Kits designed specifically for the deployable components (for example, Airbags or Seatbelt pretensioners) of the restraint harness should be used. Available Wiring Pigtail Kits can be identified in the wiring connector face view.
Warning: Do not repair or service restraint component connector terminals. if restraint connector terminals need repair. replace with the service connector pigtails. Failure to follow this instruction may result in incorrect operation of the vehicle safety restraint, which increases the risk of serious personal injury or death in a crash.
Terminal not properly seated
1 = Locked terminal
2 = Male half
3 = Female half
4 = Seal
5 = Intermittent contact
6 = Unlocked terminal (Hidden by wire seal)
7 = Seal
Check for unlocked terminal by pulling each wire at the end of the connector.
Defective insulation stripping
1 = Proper crimp
2 = Insulation not removed
3 = Wire strands missing
4 = Intermittent signals through pierced insulation
Partially mated connectors
1 = Seal
2 = Displaced tab
3 = Female half
4 = Seal
5 = Intermittent contact
6 = Male half
7 = Intermittent contact
Lock may be displaced into an unlocked position; pull on the connector to verify the lock.
Deformed (enlarged) female terminals
1 = Enlarged
2 = Normal
Any probe entering the terminal may enlarge the contact spring opening creating an intermittent signal.
Insert the correct mating terminal (Location A) from the service kit and feel for a loose fit.
Electrical short inside the harness
1 = Solder coated wire to ground
2 = Harness protective tape
3 = Intermittent short
Solder coated wire pierced through the insulation of another circuit
4 = Grounding foil
Electrical short within the harness
Splice tape removed
1 = Intermittent short
Splice covered
2 = Wire strand
3 = Splice tape
4 = Harness tape
Broken wire strands in harness
1 = Wiring harness tape
2 = Wiring strand
3 = Broken strands intermittent signal
4 = Circuit insulation
Remove the tape and flex/feel each circuit for a reduction in diameter at break.
Recommended splicing method - Solder (For 16 AWG/1.0mm and Smaller Diameter Wire Only)
Note: Cut splice coe circuit at a time noting the original wire to connector pin locations. This will avoid miss-connections.
1. Disconnect battery ground cable.
2. Strip wires to appropriate length.
3. Install heat shrink tubing.
4. Twist wires together.
5. Solder wires together.
NOTE:
- Use rosin core mildly-activated (RMA) solder. Do not use acid core solder.
- Use heat shrinkable tubes marked with ES-1 (16-22 AWG/ 0.5-1.0mm) or ES-2 (10-18 AWG/ 0.8-5.0mm) to seal wire splice.
6. Evenly position heat shrink tubing over wire repair.
NOTE: Overlap tubing on both wires.
7. Use shielded heat gun to heat the repaired area until adhesive flows out of both ends of heat shrink tubing.
NOTE: On smaller wire, use pliers to gently squeeze the ends of the heat shrink sleeve (while heat shrink is still warm) to ensure a tight fit and close any air gaps.
8. Reconnect battery ground cable.
Recommended splicing method - Crimp (For 10-22 AWG(0.35-5.0mm Diameter Wire to Like Wire Diameter)
Note: Cut and splice one circuit at a time noting the original wire to connector pin locations. This will avoid miss-connections.
1. Disconnect battery ground cable.
2. Strip 6.35mm (1/4 in) of insulation from each wire end, taking care not to nick or cut wire strands.
3. Install heat shrink tubing.
NOTE: Use heat shrinkable tubes marked with ES-1 (16-26 AWG/ 0.13-1.0mm) or ES-2 (10-18 AWG/0.75-5.0mm) to seal wire splice.
4. Select appropriate wire splice for the wires to be spliced.
5. Identify the appropriate crimping chamber on the Rotunda 164-R5901 Pro-Crimper by matching the wire size on the dies with the wire size stamped on the butt splice.
NOTE: Rotunda 164-R5901 Pro-Crimper is the only tool that can be used with these splices.
6. Center one end of the wire splice in the appropriate crimping chamber.
7. If visible, be sure to place the brazed seam toward the indenter.
8. Insert stripped wire into the barrel.
9. Holding the wire in place, barrel squeeze tool handles appropriate ratchet releases.
10. Repeating steps 5-7, crimp the other half of the splice.
Note: It is recommended to apply solder at the barrel.
11. Check for acceptable crimp.
a. Crimp should be centered on each end of the butt splice.
b. Wire insulation does not enter butt splice.
c. Wire is visible through inspection hole of splices.
12. Evenly position supplied heat shrink tubing over wire repair.
13. Use shielded heat gun to heat the repaired area until adhesive flows out of both ends of the heat shrink tubing.
14. Reconnect battery ground cable.
This chart is to be used when pigtails or terminals are of different wire gauge than the vehicle harness.
