minn kota terrova 80 seems to be only running on 12v

[R B]

I have 2 new batteries and even when the onboard charger is plugged in, the tests lights on the Terrova all light up but are very dim. The motors turns very slowly and it seems to be running at half speed if that.Has anyone had this happen before?

 

[ajgraz]

Is this something that just started happening (after some time functioning correctly), or is this an all-new install?

What is the length of your wire run, wire gage, etc? What kind of trolling motor plug (if any) are you using? You sure all your connections are good and clean?
(Trying to get an idea of your voltage drop, good connections, etc.)

What kind of charger you got? Is it a smart charger that gives an indication of battery condition / charge? What kind of batteries? You say the batteries are new, any chance one (or both) of them are bad right from the store? (it happens!) Maybe go get those load-tested. Got a multimeter?
(Could be just a bad battery)

Do you happen to have two other known good car/boat batteries and a couple sets of jumper cables or such you could use to rule out a problem inside the TM's electronics / internals?

(I'm wanting to get one of these GPS anchor TM's myself, but I'm starting to get scared regarding their reliability!)

 

[R B]

The problem just started last weekend. New batteries were installed over the winter. My buddy did push a tackle box against the TM plug and it shorted out the wire just past the plug last year. I spliced the wires on the water and always wanted to redo it because I felt it was a bit too short. Maybe inside connection is coming loose from plugging and unplugging the unit each time. This will be a good starting point.

 

[R B]

Found the problem. One of the four inline fuses was broken.