How to Install a Transom Mount Fishfinder Transducer

A fishfinder is an invaluable tool for most anglers, especially bass fishermen. The accuracy of a fishfinder depends on the proper installation of the transducer, whether the transducer is a through hull transducer or a transom mount. Most boat owners order some type of fishfinder or depth finder when they purchase a new boat. Others prefer to save a little money by installing it themselves. Installing a transom mount transducer takes less than an hour and can be done by most boat owners.

Things You'll Need

• Masking tape
• Pencil
• Drill bit set
• Cordless drill
• Screwdriver
• Marine silicone sealant
• Straight edge
• Phillips screwdriver

Instructions

1. Select the location for the transducer on the transom of the boat. Choose a location that is away from prop wash, free of turbulence and is in the water at all times. Cover the area with masking tape to prevent the gelcoat from chipping when drilling pilot holes.

2. Hold the mounting template up vertically to the mounting area and over the masking tape, ensuring that the lower corner of the template closest to the centerline of the boat meets with the lower edge of the transom. If the transducer does not come with a mounting template, use the holes in the mounting bracket as a template.

3. Mark the location of the mounting holes by poking a sharp pencil through the template where the template indicates the location of the mounting holes. Remove the template.

4. Insert a drill bit into the chuck of a cordless drill. Choose a drill bit that is slightly smaller than the diameter of the mounting screws included with the transducer. Drill pilot holes at each of the pencil marks. Ensure the holes are no deeper than the length of the mounting screws. Remove the masking tape.

5. Align the holes on either side of the transducer with the transducer mounting holes on the mounting bracket. Insert the machine screws provided with the transducer through the holes on either side of the transducer while holding a mounting nut on the other side of the hole. Thread the machine screws into the nuts and snug them up with a screwdriver, but do not tighten.

6. Open a tube of marine grade silicone sealant. Coat the threads of the self-tapping screws used to attach the mounting bracket to the transom with the sealant. Put a dab of sealant on each mounting hole. Slip the mounting screws through the transducer mounting bracket and thread them into the mounting holes with a Phillips screwdriver. Ensure that the corner of the bracket closest to the centerline of the boat aligns with the lower edge of the transom. Tighten the screws.

7. Adjust the transducer so that the front of the transducer is either level with or sits higher than the rear of the transducer. Tighten the machine screws.

8. Select the position for a hole in the transom large enough to accommodate the transducer cable. Position the hole directly above the transducer, and above the waterline. Put a piece of masking tape over the hole location. Drill the hole. Hold the cable cover over the hole. Mark the location of the cable cover mounting holes on the masking tape. Drill pilot holes at each of the pencil marks with drill bits that are slightly smaller than the self-tapping screws used to attach the cable cover to the transom. Remove the masking tape.

9. Put two pieces of masking tape on the transom, equidistant between the transducer and the hole for the transducer cable. Extend a straight edge between the transducer and the transducer cable hole. Mark a vertical line on each piece of masking tape. Hold the U-shaped portion of a cable clamp over each line on the two pieces of masking tape. Slip the pencil through the mounting hole of the cable clamp and mark the position for the pilot holes for each clamp. Drill pilot holes for the cable clamps at the pencil marks. Remove the masking tape

10. Feed the transducer cable through the hole and through the boat to the fish finder. Plug the transducer cable into the back of the fish finder.

11. Put a dab of marine silicone sealant on the threads of the self-tapping cable clamp mounting screw and over the pilot hole of the cable clamp. Slide a cable clamp over the transducer cable near the bottom hole. Allow about 3-inches of slack in the transducer cable, between the cable clamp and the transducer. Slip the screw through the mounting hole and thread it into the transom with a Phillips screwdriver. Install the upper cable clamp in the same manner, leaving no slack between the upper and lower clamps.

12. Pack the transducer cable hole with marine silicone sealant. Install the cable cover in the same manner as the cable clamps. Pack the area between the transom and the cable cover with marine silicone sealant, completing the installation of the transom mounted fish finder transducer.

Tips & Warnings

• Do not drill pilot holes any deeper than the length of the screws.

• Always use safety glasses when operating power tools.