LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2011 >> S65 >> Repair and Diagnosis >> Electrical >> Motors, Switches, Relays >> Fasteners & Wiring - General Information -- S-Class (221) >> General Information >> Assessment of damage in wiring harnesses - AH00.19-P-1000-05A

Assessment of damage in wiring harnesses - AH00.19-P-1000-05A

Always assess the damage thoroughly before repairing the wiring harnesses.

The following criteria must be observed: 

Type of damage: 

Cause of damage: 

Scope of the damage: 

Repair options: 

OVERVIEW OF CAUSES FOR DAMAGE TO WIRING HARNESSES

Type of damage Possible causes for damage Possible scope of damage Remedial action
Scorching/overheating 
  • Through external overheating: With contact with hot components (e.g. exhaust system), during welding and soldering work, painting and drying work
  • Fire
  • By means of internal overheating caused by excessive electric currents:
    • with short circuits at defective components or lines
    • with use of insufficient cable cross sections
    • with incorrect fusing (incorrectly performed installations or repairs)
    • with short circuits caused by bridging (e.g. at wire ends that are not insulated, damaged insulation)
  • Insulation and wires damaged
  • Connector housing deformed
  • Open circuit in wiring
  • Insulated hard and cracked
  • Prevent contact with hot components (e.g. exhaust system) by using different routing or approved insulation measures
  • Protect lines from overheating during welding and soldering work, painting and drying work (e.g. with the help of shields, remove lines in the repair area if possible)
  • Use required cable cross sections, perform repairs and installations correctly (pay attention to fusing, avoid damage to insulation or repair using the specified repair method)
Chafing, clamping, crushing, severing 
  • Lines routed or secured incorrectly
  • Damage as a result of an accident
  • Damage to cable when boring holes or when screwing sheet metal screws into the body
  • Lines get pinched in clamps or trim parts
  • Insulation and wires damaged
  • Lines or connections to contacts
  • High line resistance
  • Short circuit to ground and power
  • Route and attach lines correctly
  • Check lines after accidents for signs of damage
  • Check and pay attention to line routing
  • Do not pinch lines during the assembly of panels, correct line routing if necessary
Fatigue 
  • Lines routed or secured incorrectly
  • Excessive stress
  • Open circuit in wiring
  • Adjust installation and attachment of lines to local conditions and loads
Corrosion 
  • Due to contact with acids or aggressive fluids (e.g. brake fluid, antiseize, coolant additives, fuels, lubricants), water penetration due to defective seals, use of high pressure cleaner
  • Wiring harness covered in paint after paint repair
  • Hardening of insulation due to contact with an incompatible agent (e.g. solvent)
  • Line open circuit, contact pairing not longer conductive (transition resistances)
  • Insulation and wires damaged
  • Lines or connections to contacts
  • High line resistance
  • Components with sharp edges
  • Corrosion
  • Avoid contact with acids, aggressive fluids, and incompatible substances (e.g. solvents)
  • Replace defective seals, avoid using high pressure cleaners
  • Mask off lines before painting
Assembly fault 
  • Use of incorrect tools, e.g. wrong crimper or wrong release tool
  • Damaged contacts or lines due to use of unsuitable test tools (e.g. probes)
  • Lines pinched or screwed in
  • Loose contacts in plug connections
  • Wrong contacts crimped
  • Undesirable transition resistances
  • Open circuit in wiring, short-circuit
  • Insulation damaged
  • Use only approved tools (e.g. special tools) and use them correctly
  • Do not damage contacts by using test tools (e.g. use measurement or test cables)
  • Pay attention to correct routing and attachment when mounting components or lines
OVERVIEW OF AUTHORIZED REWORKING ON WIRING HARNESSES

Type of fault Remedial action
Faulty contact part   
Contact part - missing
- wrong part
- deformed
  • Install new contact part
Contact part not engaged properly
  • Latch contact part, then check, and replace if necessary
Not all individual wires are crimped
  • Cut off contact part and install new part
Insulation also crimped
  • Cut off contact part and install new part
Conductor not far enough in contact part
  • Cut off contact part and install new part
Contact part not tin-plated
  • Cut off contact part and install new part
Sleeve - oxidized
- wrong part
  • Cut off contact part and install new part
Not soldered properly/dry solder joint
  • Resolder contact part and replace if necessary
Plug-in area full of solder
  • Cut off contact part and install new part
Fault with housing   
Screw connections loose
  • Tighten screw connections using an adjusted torque wrench, replace if necessary
Screw connections - wrong part
- damaged
  • Install new screw connections (cable connectors)
Coupling housing or plug housing damaged
  • Install new coupling or housing
  • Check contact and replace if necessary
Coupling housing or connector housing not closed properly
  • Close coupling or housing properly
Cap screw in handle recess - missing
- loose
  • Tighten cap screw, replace if necessary
Cable fault   
Insulating tubing damaged
  • Rewrap with PVC tape
Insulation damaged
  • Cut through affected line at damaged area and repair using Raychem repair method
Insulation pulled up
  • Cut through affected line at damaged area and repair using Raychem repair method
Wrapping defective
  • Rewrap
Splashes of solder on cable
  • Carefully remove splashes of solder using a suitable tool without sharp edges.
Grommet - missing
- wrong part
- installed incorrectly
- damaged
  • Pull on new grommet, or install correctly