Lowrance LMS-520C blowing fuse

[barbuckle]

I have a weird one for you all. I have a Lowrance LMS-520C. I know I know old unit but it does the job for now. I replaced my batteries this winter and I’ve been playing with the unit in my garage. Twice now I’ve gone out to play and the fuse has been blown. This never happened last year with the old battery. I wired everything the same way with the new battery and I’m lost as to why it is doing this.

I have a minn Kota battery tender always plugged in while the boat sits in the garage. Could that be the problem pushing to much to the battery causing the fuse to blow? Thanks for any help you might have!

[CatFan]

Fuse isn’t going to blow from battery or charger. Something downstream like the connector or the unit itself.

What size is the fuse that is blowing?

[barbuckle]

Fuse isn’t going to blow from battery or charger. Something downstream like the connector or the unit itself.

What size is the fuse that is blowing?

It’s a 3 amp fuse.

[CatFan]

Any NMEA or Ethernet connection?

[barbuckle]

Any NMEA or Ethernet connection?

Nope. It’s a pretty basic setup.

[Stratos21XL]

Try running a temp power and ground wire directly from the battery to the unit and see if it still blows the fuse...if it does then you know it’s something inside the unit.

[kennybryan]

Also CLEAN your electronics connections from the battery all the way to the units POWER plug. Get some dielectric grease from auto parts store and use this to help inhibit CORROSION electronics biggest issue. Add VOLTAGE to your screens with EDIT OVERLAY. Sound advice above too.

[OkieBud]

Try running a temp power and ground wire directly from the battery to the unit and see if it still blows the fuse...if it does then you know it’s something inside the unit.

[barbuckle]

Well after a lot of troubleshooting, it appears the previous owner wired it to a switch on the switchboard and that switch was bad causing the fuse to blow any time I was moving it.