How to fix a jack plate when jack plate motor runs with jumped wires: First check and replace the 40-amp fuse. The 40-amp fuse is located on the red wire that comes from the relay harness and is connected to either the (+) battery post or the main power switch. Depending on the year your jack plate was made the fuse holder cover will be either blue or black. For best results, replace the fuse even if it does not look blown.
If your jack plate motor still only runs with jumped wires to the battery, check for loose connections. Follow the wires connecting to the jack plate. Check all wire connections to make sure a wire hasn't come loose.
If your jack plate motor still only runs with jumped wires to the battery, it is likely that the wiring harness needs to be replaced.
If your unit is less than one year old, contact T-H Marine for a replacement. If your unit is more than one year old, we recommend going to your nearest boat dealership or contacting a retailer for replacement parts.