Elite electrical teams do not rely on memory; they run checklists. A consistent routine catches the loose lug or low battery before the robot rolls onto the field.
Pre-match checklist (run every match in the queue):
- Battery: freshly charged and load-tested 'Good' (resting ~12.6-13V, low internal resistance on a Battery Beak). Battery securely strapped in. SB-50 fully mated and tied so it cannot pop.
- Main breaker: seated and reset (button in).
- Connections: tug-test battery lugs and PD input lugs. They must not rotate by hand.
- Fuses: all PD fuses seated hard.
- Power-on test: roboRIO Power LED solid green, Status LED off after boot, PD LED green, RSL solid (disabled).
- Comms: Driver Station shows green comms, code, and joystick; battery voltage reads sane (>12V at rest).
- CAN: no red device LEDs; a quick enable shows all motors respond and the RSL blinks.
- Bumpers/cover do not pinch any wires.
Post-crash / 'it died on the field' triage:
- Read the Power LED. Amber -> it browned out; check battery and current limits, swap to a fresh load-tested battery, review the match log for the brownout timestamp.
- Read the DS log (Driver Station Log Viewer): look for brownout events, comms drops, and the 12V fault count. This tells you whether it was power, comms, or code.
- Jostle-test CAN if a specific mechanism died: a hard hit commonly loosens a CAN or WAGO connection. Watch for red LED blips.
- Check the main breaker did not trip from a stall or short.
- Inspect for physical damage: a pinched or severed wire from the collision, a popped SB-50, a connector pulled out of a WAGO.
- Confirm before re-queuing: re-run the pre-match checklist; do not send a robot back out on a guess.
Documentation that pays off: keep a CAN ID map, a wiring diagram, and labeled wires so anyone on the team can debug. Mark any dropped or suspect battery as faulty until it is re-tested; never lift a battery by its wires. These habits turn chaotic between-match scrambles into a calm two-minute routine, which is exactly what wins close eliminations.
the part worth keeping
Key takeaways
- Run a fixed pre-match checklist every match: battery load-tested, lugs tug-tested, fuses seated, LEDs green, comms and CAN verified.
- After a death on the field, read the Power LED and the DS log first to classify it as power, comms, or code before touching hardware.
- Maintain a CAN map, wiring diagram, and labeled wires; retire suspect batteries until re-tested and never lift a battery by its wires.
Electrical & WiringCommon Mistakes & Troubleshootinglesson 5 of 5
Keep going
Take the quiz+10 XP with an accountwhere this came from
Sources and corrections
This lesson is AI-assisted: drafted from primary sources, then reviewed and edited by hand. Errors still get through. When one is reported we fix it and write down what changed, in public, in the corrections log.
sources and further reading
- docs.wpilib.orgWPILib: Wiring Best Practices (maintenance cadence)
- firstfrc.blob.core.windows.net2026 FRC Inspection Checklist
clipped to this lesson
Articles that go further on this
The lesson gets you through the topic. These go wider on it, and they read in one sitting.
- 7 min readFRC LED Lights: Wiring, Power Budgeting, and the WPILib AddressableLED APIHow to wire addressable LEDs off the PDH's switchable channel, budget their current draw, and use WPILib's AddressableLED API to signal robot state./blogread it
- 8 min readFRC Battery Guide: Charging, Care, Testing, and SafetyFRC battery guide: how to charge, care for, test with a Battery Beak, wire the SB50 connector, and safely handle your 12V FRC battery fleet./blogread it
- 7 min readFRC "No Robot Code" & Driver Station Won't Connect: Full Fix ChecklistA verified, step-by-step FRC troubleshooting decision tree for "No Robot Code" and a Driver Station that won't connect to the roboRIO — most common causes first./blogread it
answer sheet
Lesson quiz
All 4 right completes the lesson. Miss one and only that question comes back, anything you already answered correctly stays banked.
0 of 4 answered
01The robot died on the field. What does the triage routine have you do first?
02During post-crash triage you read the Power LED and it is amber. What does that indicate?
03On the pre-match checklist, how should the power connections be verified?
04How should you handle a dropped or suspect battery?
Answer every question to submit.
All 35 lessons in Electrical & Wiringopenclose
01 / prerequisites
02 / control-system-components
03 / power-battery-breakers
04 / motor-controllers-can-bus
05 / connections-rules-troubleshooting
06 / worked-examples-mini-projects
- Not read yet:Mini-Project 1: A Single-Motor Test Stand from Battery to Spin
- Not read yet:Mini-Project 2: Current-Limited Drivetrain (CTRE and REV)
- Not read yet:Mini-Project 3: A Live Power-Monitoring Dashboard
- Not read yet:Mini-Project 4: A Switchable Channel for Lights and Vision
- Not read yet:Mini-Project 5: CAN Device Bring-Up with Tuner X and the Hardware Client
07 / common-mistakes-troubleshooting
08 / advanced-techniques-case-studies