If your Thetford fridge isn’t working on 12V power while the engine is running, the issue may be caused by a faulty fridge relay located in the rear fuse panel. This guide helps you check the relay yourself, using the video and PDF linked below.
Video: Relay Inspection for 12V Fridge Power
A PDF guide of this video will also be available for download.
Step-by-Step Fridge Relay Check
Step 1: Access the Rear Fuse/Relay Box
Locate the rear fuse compartment (accessible through the back of the vehicle).
Remove the black plastic cover to reveal the relays and fuses.
Step 2: Identify the Fridge Relay
There are three vertically aligned relays inside:
Top – Ignition
Middle – Electric Step
Bottom – Fridge ← (this is the one you're checking)
These relays are standard and interchangeable, which allows for quick testing.
Step 3: Inspect the Fridge Relay
Remove the bottom relay and check for the following:
Burnt or smoky smell
Melted plastic or blackened pins
Bent or missing pins (should be 5 intact metal pins)
? Take a photo of any visible damage for reporting.
Step 4: Swap and Test
If no visible damage is found:
Try swapping the fridge relay with one of the others (e.g., ignition or step).
Reinsert and start the engine — check if the fridge now switched on 12V.
✅ If the fridge starts working after the swap, the original relay is likely faulty.
❌ If not, record your findings anyway and report them.
Step 5: Let Us Know What You Find
Once you've completed the steps above, contact our On-Road Care Team with:
Any photos of damaged relays
What happened after swapping the relays
Call: 1300 016 532
Was this article helpful?
That’s Great!
Thank you for your feedback
Sorry! We couldn't be helpful
Thank you for your feedback
Feedback sent
We appreciate your effort and will try to fix the article