If this is under soil and not concrete, try this. Go to your nearest Big Orange store at about 7:00 am. Locate a couple of fellows hanging around the front area who dress and look like they are from outside your county line. I promise they will work at an affordable rate. Have them re-dig the thing and this time you can put in pvc and upgrade the whole shebang for the customer. Make sure though when you hire your new helpers, that you follow all state and federal hiring laws and also make sure that you have the proper workmans comp and other required insurance in place. This will probably be a less costly solution than trying to TDR the wire and locate a nick, unless you have ready access to the equipment.
