How Do I Identify Incorrect Wiring on My Actuator System?
Incorrect wiring is the most common cause of problems in newly installed actuator systems. This article covers the key signs of miswiring and how to identify and correct each one quickly.
Common Signs of Incorrect Wiring
| Symptom | Likely Wiring Error | Fix |
|---|---|---|
| Extends when button says retract | Motor wires reversed at output | Swap the two motor wires at the control box output |
| Actuator runs continuously, never stops at end of stroke | Limit switch (3rd wire) bypassed or not connected | Connect the white/yellow limit switch wire into the correct circuit path |
| Actuator stops immediately in one direction only | Limit switch wired only in one direction's circuit | Verify limit wire is in series for both extend AND retract paths |
| No movement, no sound, no LED | Polarity reversed on PSU input to control box | Swap positive and negative on PSU input terminals |
| Sparks or immediate fuse blow | Short circuit — power and ground crossed | Power off immediately; map all connections against wiring diagram before re-energising |
| Feedback reading wrong direction | Potentiometer Vcc and GND swapped | Swap the power and ground wires on the pot feedback circuit |
How to Verify Your Wiring
1. Download the wiring diagram
Visit the PA Wiring Diagrams page and find the diagram for your specific actuator and control box combination. Print it or have it open on a second screen.
2. Trace each wire before powering on
Before applying power to a new installation, physically trace every wire from source to destination and compare to the diagram. Mark each wire with a label or coloured tape if it helps.
3. Use the multimeter first, power second
Use continuity and resistance tests to verify connections before powering on. This catches wrong-terminal insertions and shorts without risking component damage.
📖 Full wiring guide: 12 Volt Linear Actuator Wiring — covers all common wiring configurations with photos and diagrams from PA engineering.