The red LED indicates an error In most cases, the tear or point of short circuit can be seen with the naked eye. If this is not the case, try the following:
Using a commercially available LED, place the pins of the LED so that they are touching the two screws that are connected to the brown wires. This is where the electrical impulses originate. If the LED flashes, the electrical polarisation is correct. If the LED does not flash, turn the LED round and try again. It should flash now. Then, move a small distance further along the aluminium strip and repeat the process. If the LED doesn't flash, it means that the tear or point of short circuit is somewhere between the current and the last point you checked. Go back to the last functional point. Then, reduce the distance to the next point you check until, once again, the LED doesn't flash. Now, you should be near to the damaged section, and it should be easy to locate. Clean the damaged section with a cloth moistened with solvent or alcohol (methylated spirit), and tape over a aluminium strip approximately 5 cm in length. The green LED should now indicate that the slug fence is working correctly.