Why are there no lights on the DC Solar Pump Controller?

TROUBLESHOOTING STEPS

• Check if the light bar is plugged in properly. If it is not, it can prevent the lights coming on and showing what the pump controller is doing.
• Sometime the light bar can fail which can cause the controller to stop operating the pump normally. Unplug the light bar to test if the pump will start running.

• Check the solar isolator (between the solar panels and the pump controller).
• Ensure it is switched to the “I” (ON) position.
• If it is in the “O” position (OFF), the controller will not receive any power.

Note - not all pump controllers have this switch.

• Check the solar/battery mode switch in the top right corner of the board is set to Solar (up position) and not the centre or battery positions.

• The pump controller relies on sunlight for power unless connected to a battery or mains power pack.
• During early morning, late afternoon, or heavy cloud cover, there may not be enough solar power to activate the unit.
• Wait until full daylight (midday) and recheck.

• Open the controller carefully.
• With the incoming power switched off, check that the solar panel wires are securely connected to P+ and P- terminals.
• Check for loose wires, burnt connections, and corrosion on the P+ and P- terminals.
• Check for damage to the power input cables.

 Test the Solar Panel Voltage

With the incoming power turned on, use a multimeter to check the voltage at the P+ and P- terminals:

• Check that the polarity of the incoming solar power is correct by placing the red (positive) probe on P+ and the black (negative) probe on P-. If the voltage is in negative numbers, the polarity is incorrect, and the wires need to swap terminals. Turn incoming power off before swapping the wires to the other terminals.
• 24V pump systems should show 35V–55V open circuit voltage (Voc)

• 48V pump systems should show 65V–109V (Voc)
• 72V pump systems should show 80V–140V (Voc)
  If the voltage is in this range but there are no lights, the issue may be inside the controller.

In some cases, the external switch (the bottom right corner of the controller) turns all the lights for the controller off and prevents it from outputting power to the pump.

• Ensure it is set to the “I” (ON) position.
• If it is set to “O” (OFF), it activates the “Tank Full” circuit and stops the controller from outputting power to the pump.
• The external switch may be faulty and prevent normal operation on the controller. Unplug the external switch from the bottom right corner of the circuit board to test is the switch is faulty.

• With the pump stopped and not running, turn the solar isolator OFF
• Wait 30 seconds
• Turn it back ON
  This will reset the controller and can clear temporary startup issues.

• Some models may have a fuse inside the controller.
• If accessible, inspect it for signs of burnt connections, corrosion, or damage.
• Replace the fuse if it is blown.

• Make sure the pump controller and pump are not operating during this check. Check each panel’s MC4 connectors by unplugging them from each other and then plugging them back into each other. This connection needs to be firm and complete to allow power flow while under load.
• Use MC4 tester or multimeter to isolate faults between solar panels if available.
• If the panels are far from the pump controller, you may experience voltage drop.
• If voltage is good at the solar panels but low at the pump controller, check the cable size is correct and in good condition.5

Conclusion:
If the controller still shows no lights and voltage is present after these checks, there may be an internal fault preventing the controller from operating. Contact Commodore Australia’s Technical Support team for further assistance.