FAQ

by admin| | Diagnosing Failures

Common Causes and Solutions of Testing Errors

Common Causes and Solutions of Testing Errors  

Finding the causes of errors then implementing the correct solution can be a confusing task. There are so many reasons an error can occur and finding the right solution can be difficult. The following table shows common errors, their causes, and possible solutions. We hope it helps you more easily fix errors found in your cables and harnesses.

We’d like to extend our sincere thanks to Trevor Morris, Gary Grahn, and to the many customers who shared their experience and insight. Their real‑world examples and troubleshooting knowledge greatly enriched this article and helped shape the guidance provided here.

Test result displaying errors.

Low Voltage

Error Example Error Message Details Potential Causes Potential Fixes
Wire Missing #2 Wires missing J1-1 J1-2 No connection between specified points (terminations)
  • Wire is missing.
  • Contact is recessed.
  • FOD is on contact.
  • Above issues exist on test fixture.
  • Contact is improperly terminated.
  • Incorrect WIRE (continuity) instruction is in test program.
  • Identify and install missing wire.
  • Check affected contacts on harness/fixture for retention/FOD. Clean FOD and insert contact/replace connector.
  • Inspect the affected wires and replace the contacts if defective.
  • Check test program against current drawing and revise the test program if necessary.
Short #3 Short J1-1 J1-2 A connection exists between specified points (nets) where there should be no contact
  • Wire strands are not captured in crimped contact.
  • Solder bridge exists between contacts.
  • Backshells/Connectors are touching during testing.
  • Nets are spliced where they shouldn’t be.
  • WIRE Instruction is missing in test program.
  • Problems exist in test fixture.
  • Examine connectors for possible wire strand or solder contact between pins. Fix any problems found.
  • Separate backshells and connectors.
  • Identify affected wires and check for incorrect splices.
  • Check test program against current drawing and revise the test program if necessary.
  • Verify test fixtures do not have shorts if run in a test without DUT. Fix any problems found.
High Resistance #1 High Resis J1-1 J1-2 A connection exists between the intended points, but the resistance is not low enough to be considered a good connection (based on connection resistance setting).
  • FOD exists on contact.
  • Test fixture is wearing out and/or adding unintended resistance.
  • Mating connection on DUT or test fixture is not solid.
  • Connection Resistance is set too low.
  • Check affected contacts on harness/fixture for retention/FOD. Clean FOD and insert contact/replace connector.
  • Ensure all connectors are mated properly.
  • Check connection resistance settings.
Miswire #4 Miswire J1-12 Net4 The wire is open to the correct contact and connected to the incorrect contact instead.
  • True miswire error exists.
  • Test fixtures are not inserted or aligned properly.
  • The test program includes an incorrect WIRE instruction.
  • The wrong test program is loaded.
  • Rewire the assembly according to the drawing.
  • Check that the part is being tested against the correct test program.
  • Check that the test fixtures are inserted/aligned correctly.
  • Revise the test program if appropriate.

High Voltage

Error Example Error Message Details Potential Causes Potential Fixes
Arc, Point-Point #144 DW Arc Error or #145 IR Arc Error (CH2)
Dielectric Failure (4250/Easy Touch)		 Electricity unexpected jumps from one net to another.
  • Nicked wires in DUT or test fixture.
  • Damaged dielectric on connector.
  • Insulation clearance on contacts is out of tolerance.
  • Exposed solder/shield strands on shield terminations.
  • Solder flowed onto wire insulation.
  • Thin insulation in DUT or test fixture.
  • Wire cut by screw or clamp during final assembly.
  • Conductive FOD is present near connectors/contacts.
  • Insulation melted by heat gun or soldering iron.
  • Worn/broken shrink tubing from excessive heat, handling, or sharp wire strands.
  • Identify affected wires and inspect them for damage/thin insulation.
  • Replace connector.
  • Remove and replace affected contacts.
  • Inspect shield terminations for exposed solder, solder that flowed onto insulation, or exposed strands.
  • Inspect strain relief for contact with wires.
  • Inspect connectors for FOD.
  • Check the proximity of the nets to the location of the arc. (Near proximity implies the arc was near the connector. Far proximity indicates the arc is in the wire bundle.)
Arc, Single #144 DW Arc Error (CH2) Electricity unexpected jumps from one net to an unknown source. (Possibly to conductive material near test area.)
  • Conductive material is too close to testing area.
  • Conductive FOD is present near connectors/contacts.
  • Nicked wires in the DUT or test fixture.
  • Damaged dielectric on connector.
  • Insulation clearance on contacts is out of tolerance.
  • Exposed solder/shield strands on shield terminations.
  • Solder flowed onto wire insulation.
  • Thin insulation on DUT or test fixture.
  • Insulation melted by heat gun or soldering iron.
  • Clean/clear testing area of foreign objects and retest.
  • Make sure conductive shells on DUT are not touching tester case or conductive surfaces.
  • Inspect connectors for FOD.
  • Identify affected wires and inspect them for damage/thin insulation.
  • Replace connector.
  • Remove and replace affected contacts.
  • Inspect shield terminations for exposed solder, solder that flowed onto insulation, or exposed strands.
  • Inspect strain relief for contact with wires.
IR Leakage Failure #150 J1-1 Has Leakage Error (CH2)
Leakage Error (4250/Easy Touch)		 There is insufficient insulation between the net and some other path to ground.
  • Moisture in air or device.
  • Damaged Insulation.
  • Contamination from soldering (flux) or other processes.
  • Insulation melted by heat gun or soldering iron.
  • Flush with dry air, apply heat, or allow to sit 24 hours, then retest.
  • Inspect affected nets for damaged/thin insulation.
  • Inspect affected nets near exposed conductor points (contacts, shield terminations, splices, etc.).
DW Current High Error #146 J1-1 DW Current High (CH2)
Leakage Error (4250/Easy Touch)		 Current level exceeded DW Max Current setting but was not a sudden spike in current. This is not common.
  • Problems like IR leakage failures.
  • A short or near short occurred after the LV test (e.g. introducing a short by moving the cable before pushing HV button).
  • Follow recommendations for Leakage and Arc errors.
  • Retest cable without moving to check for LV shorts.
Change Error #142 DW Charge > 45uC at V Error (CH2)
Overcurrent Error (4250/Easy Touch)		 The high voltage charge exceeded safety limits. Excessive capacitance in device (usually a shield or long coiled wire).
  • Make sure there is no floating metal in harness (i.e. any metal that is not connected back to a test point in the test program).
  • HV settings for the net may need to be changed to lower voltage or marked as High Cap net.
  • Uncoil the harness to reduce capacitance.

Glossary of Terms:

  • DUT – Device Under Test
  • FOD – Foreign Object Debris
  • HV – High Voltage
  • LV – Low Voltage
  • DW – Dielectric Withstand
  • IR – Insulation Resistance
  • Test Fixture – Any device used to connect the tester to the DUT

Themes from the table

  1. A surprising number of fails aren’t in the cable—they’re in the fixture or test setup.
    Multiple entries point to fixture wear/added resistance, fixture shorts, or mis‑inserted/aligned fixtures as root causes and recommend running the fixture by itself to verify it first.
  2. Contamination and debris (FOD/flux/moisture) are repeat offenders.
    Low‑voltage issues cite FOD on contacts; high‑voltage issues cite conductive FOD near connectors/contacts; insulation leakage is linked to moisture or flux contamination.
    Humidity lowers insulation resistance and flux acts as a “leaky insulator,” causing IR/leakage or even arc/shorts—problems that can be invisible without disassembly.
  3. Program/setup mistakes are common—and preventable.
    Wrong or outdated test programs, missing/incorrect WIRE instructions, and overly strict connection‑resistance thresholds appear repeatedly as causes.
  4. Mechanical/assembly realities drive most low‑voltage failures.
    Shorts and opens often trace to nicked wires, solder bridges, stray strands, recessed or poorly terminated contacts, or incomplete mating.
    Our “Causes of Bad Connections” table reinforces the same patterns (loose crimps, flux on mating surfaces, contact retention) and ties them to open/intermittent/high‑resistance symptoms.
  5. High‑voltage errors cluster around clearance, damage, and capacitance.
    Arc/point‑point errors suggest thin/damaged insulation, exposed strands, or inadequate contact clearance; “Change/Overcurrent” flags excessive capacitance (long/coil, shields), which can be mitigated by uncoiling and treating nets as high‑capacitance in settings.
    Our HV primer adds that testers can’t distinguish “true insulation weakness” from “unaccounted capacitance” unless you tune the HV settings.