Mars Caravan Pump Not Working? Switch, Fuse & 12V Checks

Pump Won’t Turn On: Power Checks & What to Inspect

Pump Won’t Turn On: Power Checks & What to Inspect

If your water pump won’t turn on at all (no sound, no vibration), the cause is usually electrical: the pump switch is off, the 12V system is off/low, or a fuse has blown.

This guide covers safe checks you can do in your Mars caravan before lodging a support ticket.

Quick safety note

  • If you suspect water has leaked onto electrical components, keep the pump OFF and log a ticket.
  • Do not bypass fuses or wiring.

Step-by-step troubleshooting

Step 1) Confirm you’re testing correctly

  • Turn the pump switch ON (control panel or local switch, depending on model).
  • Open a tap fully — many systems only run the pump when a tap is opened (pressure drop).

Step 2) Check the 12V system is ON

  • Confirm the battery isolator is ON.
  • Check the 12V master switch on the control panel (if fitted).
  • Check battery level: extremely low batteries can cause 12V items to stop working.

Step 3) Check the pump fuse

Locate the 12V fuse panel and find the circuit labelled “Water Pump” (or similar).

  1. Turn the pump switch OFF.
  2. Remove the pump fuse and inspect it for a broken/burnt strip.
  3. Replace with the same amp rating fuse only.
  4. Turn pump back ON and re-test at a tap.

Step 4) Listen for any sign of life

  • Nothing at all: likely switch/fuse/power/connection issue.
  • Clicking only: could be low voltage or a failing connection.
  • Starts then stops instantly: could be a fuse blowing or low voltage under load.

Step 5) If you’re plugged into 240V, confirm batteries are charging

Your pump still relies on 12V battery power. If batteries are flat and not charging, the pump may not run.

  • Plug into 240V and ensure RCD/breakers are ON.
  • Check the battery monitor: does voltage/% rise?

Common causes

  • Pump switch OFF (control panel/local switch)
  • Battery isolator OFF / 12V master OFF
  • Low battery voltage
  • Blown pump fuse
  • Loose wiring connection at fuse panel, switch, or pump (less common)
  • Faulty pump (rare, but possible)

When to stop and contact support

Log a ticket if:

  • The pump fuse blows immediately after replacement
  • 12V power is on and batteries are healthy, but pump won’t run
  • You suspect water has leaked onto electrical parts
  • You see melted wiring, smell burning, or components get hot

What to include in a support ticket (so we can help fast)

  • Your model + year (and VIN/chassis number if available)
  • Photo of your control panel showing pump switch (if applicable)
  • Photo of the 12V fuse panel (pump fuse label visible)
  • Photo of your battery monitor (voltage/% while testing)
  • Short video: turning pump ON, opening tap, showing no pump response
  • Tell us if the fuse blows, and what else was running at the time

Next in this series: Water Leaks — Immediate Steps + How to Help Us Diagnose Fast

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