Wire Harness Continuity Test With a Bluetooth Multimeter

1. Isolate the harness from power. Check the connectors are clean and undamaged.
2. Short the two probes together and press REL, so the lead resistance is taken off every reading.
3. Start a run from a harness template. Two starter templates ship with the app: ST-1, a 20-pin continuity check, and ST-2, a 12-conductor harness check with a stage field.
4. Touch the probes to the first pair of pins. When the reading is steady, the app captures it, shows PASS or FAIL against the limit, and moves to the next step.
5. Lift the probe or change the reading clearly before the next capture. That stops the same value from being saved twice.
6. If a pin fails or you slip, go back and recheck it. Redo, skip and go back are all there, and earlier attempts are kept.
7. At the end, the summary shows PASS, FAIL or INCOMPLETE, with the failed pins listed. Export the run.

Check a harness at each stage, and keep the stage in the record:

1. After lead-out, when the wires are cut, crimped and numbered.
2. After the connectors go on, when every pin is in its connector.
3. Installed, before power-on.

Add a run field called Stage, and fill it in at the start of each run. Three runs give three files, so each stage has its own record. ST-2 already asks for the build stage.

For aircraft harnesses the limit per conductor depends on the wire gauge and the length. The FAA advisory circular AC 43.13-1B lists the maximum resistance per 1,000 feet for tin-plated copper conductors at 20 °C (Table 11-9, para 11-66 d(2)). The circular is guidance. Your drawing and the maintenance manual win. The values below are example; set your own limits.

The last column is computed: 16.20 Ω per 1,000 ft times 10 ft is 0.162 Ω. Add the contact allowance your drawing asks for. Put gauge and length in as typed value steps, and set the limit on each pin step Pro.

Some points for aircraft work:

• Zero the leads first. A limit like 0.162 Ω is small next to the resistance of a pair of test leads, and your meter's resolution on its low range may be too coarse for it. Check its data sheet. Press REL with the probes shorted, and write the lead resistance in a typed step.
• Probe at the test point. Do not pierce the insulation. Use the connector contact or a test point.
• Shell isolation. For each pin to the connector shell, set the step to expect open. The step passes on OL Pro.
• Insulation resistance needs a megohm tester, not a multimeter. Read it on that tester and type the value into a step; it is marked manual.
• Limits and sign-off. A test file is your record, not a certification. See aircraft electrical test records for what the file is and what it is not.

The PDF lists each step with its value, unit, limit and result, with the notes and photos you added. The Excel report has real numeric cells and PASS and FAIL cells. Pro adds your company name and the technician's name to the header Pro. CSV is there for any other tool. The app does not connect to ERP or maintenance systems; you attach the exported file by hand.