Garmin GPSMAP 421 Installation Instructions Manual - Page 4

Browse online or download pdf Installation Instructions Manual for Marine Equipment Garmin GPSMAP 421. Garmin GPSMAP 421 12 pages. Marine navigation equipment
Also for Garmin GPSMAP 421: Reference Manual (2 pages), Technical Reference (42 pages), Important Safety Information (48 pages), Installation Instructions Manual (28 pages), Template Manual (2 pages), Declaration Of Conformity (1 pages)

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Garmin GPSMAP 421 Installation Instructions Manual

To mount the transducer on a transom:

1. Position the transducer mount at the selected transom location. Make sure the transducer is parallel with the water line. Mark the center

locations of each hole on the transducer mount.

Apply marine sealant to all screw

threads to prevent water from

seeping into the transom.

2. Drill

in. (4 mm) pilot holes approximately 1 in. (25 mm) deep at the marked locations. To avoid drilling the holes too deep, wrap a piece of

tape around the bit at 1 in. (25 mm) from the point of the bit.

3. Apply marine sealant to the 5 × 30 mm screws (B). Attach the transducer assembly to the transom using the 5 × 30 mm screws. Adjust the

transducer assembly to extend beyond the bottom of the transom approximately

aluminum hulls. Adjust the transducer assembly to be aligned parallel with the bottom.

4. Tighten the 10-32 locking nut until it touches the mounting bracket, and then tighten

5. Place the first cable clamp (F) on the transducer cable, approximately one third of the distance between the transducer and the top of the

transom.

6. Mark the location. Drill a

7. Attach the cable clamp using one of the 4 × 12 mm screws (D). Coat the screw with marine sealant before installation. Repeat steps 5 and 6

using the other cable clamp.

8. Route the transducer cable to the GPSMAP 400/500 series chartplotter.

NotIce: Avoid routing the cable close to electrical wires or other sources of electrical interference.

9. Test the transducer installation after you complete the GPSMAP 400/500 series chartplotter installation. See page 9.

Mounting a Transducer on a Trolling Motor

1. With the ridges of the band facing up, slide the large cable tie through the slot on the transducer mount until equal lengths extend on both

sides of the mount.

NotIce: For cold water and heavy timber or debris areas, a metal 4-5 in. (100-125 mm) worm gear clamp is recommended instead of the plastic

cable tie.

2. Position the mount gasket on the curved top of the transducer mount.

3. With the front of the transducer pointed away from the trolling motor propeller, place the transducer

assembly against the motor body of the trolling motor.

4. Wrap the two ends of the cable tie around the motor body. Place the pointed end of the cable tie through

the fastener hole on the opposite end and pull it through until it is snug but not tight. (The cable tie clicks

when you pull it.)

5. Position the transducer so that it is parallel with the bottom when in use, making sure the gasket is

aligned properly. Pull the cable tie end until tight. Trim off the excess if necessary. Tighten the locking nut

until it touches the mounting bracket, and then tighten

The transducer should

extend

in. (. mm)

below a fiberglass hull or

in. (9.5 mm) below an

aluminum hull.

Mount the transducer parallel

with the bottom.

in. (3.2 mm) pilot hole approximately

Ensure that the transducer is

below water level when the boat

is on plane at high speed.

Do not mount the transducer directly in the path of the

propeller. The transducer can cause cavitation that may

degrade the boat performance and damage the propeller.

in. (3.2 mm) on fiberglass hulls or

in. (9.5 mm) deep.

turn more. (Do not overtighten.)

Mount the transducer

cable cover far above

the waterline.

turn more. (Do not overtighten.)

Front of the transducer

GPSMAP 400/500 Series Installation Instructions

in. (9.5 mm) on

Cable tie