Assessment of damage in wiring harnesses - AH00.19-P-1000-05A
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2014 Mercedes-Benz C63 AMG, 2013 Mercedes-Benz C63, 2012 Mercedes-Benz C63, 2011 Mercedes-Benz C63, and 2011 Mercedes-Benz C350. However, it is still accessible from the selected car via links, so may be relevant.
Always assess the damage thoroughly before repairing the wiring harnesses.
The following criteria must be observed:
Type of damage:
- Damage caused by scorching/overheating, chafing, clamping, crushing, severing, fatigue, corrosion, cable chewed by an animal, assembly fault.
Cause of damage:
- The cause for the damage must be determined to ensure that the damage does not reoccur after the wiring harness has been repaired.
Scope of the damage:
- Which components are damaged?
- Can the extent of the damage be exactly determined?
- Can you be sure that no other components are damaged?
Repair options:
- What are the options for repair?
- Which replacement parts are available?
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
|
|
- 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
|
|
| 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
|
- 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
|
- 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
|
- Tighten cap screw, replace if necessary
|
| Cable fault |
|
| Insulating tubing damaged |
|
| 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 |
|
| 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
|