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Main PCB & Battery Control PCB Wiring Harness Manufacturing Guide

Purpose​

This guide explains how to manufacture and assemble the wiring harnesses for both:

  • The Main PCB, which handles core avionics and power distribution.
  • The Battery Control PCB (BC_PCB), which interfaces with the Main PCB and pushbutton systems.

Use the following wiring table for all of the connections TO/FROM for all of PT3’s systems: https://docs.google.com/spreadsheets/d/1INDpDhqC1wYGbbJhMCmYZ-2Rzxx5Ob4zoG5JTc_2Sps/edit?gid=2139598833#gid=2139598833

Wire Harnessing Scope​

PCB SectionDescription
Main PCBRoutes power, data, and control signals to all subsystems
BC_PCBRoutes battery HV signals, pushbutton I/O, CAN/I2C

Materials Required​

  • Wires:
    • 26 AWG silicon
    • 20 AWG silicon
    • 6 AWG silicone (HV power)
  • Crimp Tools
    • Engineer PA-09
      • JST-GH and Molex Micro-Lock compatible
    • Hex die pneumatic crimper
      • Amass connector crimp compatible
  • Wire Stripper
  • Wire Cutter

Main PCB Connectors & Housing​

Eurostyle Plug

ConnectorMating HousingCrimp Required
39511-100439510-0004No
39511-100539510-0005No

JST Connectors & Housings (1.25mm GH Series)​

ConnectorMating HousingCrimp RequiredCrimp Type
SM03B-GHS-TB(LF)(SN)GHR-03V-SYesSSHL-002T-P0.2
SM04B-GHS-TB(LF)(SN)GHR-04V-SYesSSHL-002T-P0.2
SM05B-GHS-TB(LF)(SN)GHR-05V-SYesSSHL-002T-P0.2
SM06B-GHS-TB(LF)(SN)GHR-06V-SYesSSHL-002T-P0.2
SM09B-GHS-TBGHR-09V-SYesSSHL-002T-P0.2

Molex Connector​

ConnectorMating HousingCrimp RequiredCrimp Type
207760-1281204523-1201Yes2145291000

Phoenix Contact Terminal Blocks​

ConnectorMating ConnectorPosition
181492217048543
181493517048574
183921117048574 (vertical)
181494817048585
181495117048596
177873517048596 (vertical)
181496417048607

Power Connectors​

FemaleMaleCrimp RequiredCrimp Type
XT60PW-FXT60-MNoN/A
XT30PW-FXT30-MNoN/A
LCB60PB-MLCB60-FYes91021-F.S

Other Parts​

  • Pushbutton: PVHC4F23SS344
  • Compression Lug: 7461097 (M6, 180A)

Manufacturing Instructions​

1. Wire Cutting​

  • Cut wires to specified lengths (in cm) from the wiring table.
  • No strain relief required since the lengths do not take the connectors into account and some lengths were rounded up.

2. Crimping​

  • Strip approximately 2 mm of insulation for 20 - 26 AWG cables
  • Strip approximately 9 mm of insulation for 6 AWG cables
    • Do not double crimp and apply heat shrink if necessary
  • Use appropriate crimp tool for terminals
  • Verify both conductor and insulation are captured securely.

3. Connector Assembly​

  • Insert crimped wires into JST, Molex, or Phoenix housings per the wiring diagram.
  • Match pin numbers at both ends of the cable using the table.
  • Ensure proper keying and orientation

4. Continuity Testing​

  • Perform multimeter continuity checks for each wire.
  • Verify no shorts or open wires exist.

5. Harness Bundling​

  • Use mesh sleeving, zip ties, and cable clips.
  • Route for minimal EMI, avoiding parallel runs of HV and signal cables.

Wire Color Coding Reference​

Signal TypeExamplesColor
GroundGND, HV-Black
5V PowerVDD_5V_*, 5VGray
12V Power12V, 12V_PL, 12VSWRed
CAN HighCAN1_H, CAN2_HGreen
CAN LowCAN1_L, CAN2_LGray
UART TXUART*_TX_*White
UART RXUART*_RX_*Pink
Ethernet RX+/-ETH_RX+, ETH_RX-White / Orange
Ethernet TX+/-ETH_TX+, ETH_TX-Grey / Green
Digital IOIO_*, FMU_CH*Blue
HV Battery +HV+Red
HV Battery -HV-Black

Final Checklist (Main + BC_PCB)​

  • All wires cut to correct length
  • Crimps tight and in correct connector housing
  • Pinout and polarity verified on both PCBs
  • Continuity testing passed for all connections
  • HV wires securely lugged and insulated
  • Harnesses neatly bundled and strain-relieved