Replacing the Fuse in an Automotive Vehicle Power Cable

A quick blow (fast-acting) fuse is used in all Garmin automotive power cables. The maximum amperage of the fuse can vary between devices.

You can view the sticker on the cable for the specifications of the fuse. Consult the owner's manual of your device if you are unable to locate this information.

Older devices use a cable with an 18-pin connector like the GTM 20. Fuses in the GTM 20 and similar cables can be removed by unscrewing the plastic cap at the cigarette lighter end of the plug covering the silver tip.

Newer cables like the GTM 36 and standard vehicle power cable use a different method for removing the fuse.

To Change the Fuse in These Cables:

1. Push the silver tip down with a coin
2. Turn the coin 90 degrees counter-clockwise¹
3. Remove the plastic end-piece, silver tip², and fuse³. It is not necessary to remove the spring behind the fuse.
4. Insert a new fast-blow fuse that has the same current, such as 1 A or 2 A.  Fuse size: 20mm x 5 mm or 2 cm x 0.5 cm.
5. Place the silver tip in the end piece.
6. Push in the end piece and rotate it 90 degrees clockwise to lock it back into the vehicle power cable⁴.

The fuse is blown and will need replacing if the interior is blackened, burned, or the filament inside is broken. This can also be checked using a multimeter or continuity tester.

The voltage and amperage are stamped onto one of the metal ends of the fuse. This style of a fuse can be purchased from most electronics or automotive service stores.