Motorguide Tour 82 - Marinco Plug Failure

[JohnM64]

Motorguide was DOA yesterday AM, never had a problem, worked as usual Friday.

No tripped breakers, batteries full charged. Back at home, have good voltage at receptacle.

Open up 30A Marinco plug, and see the ground wire insulation a bit fried - it appears the strain relief "strained" the insulation to help it melt though for a direct short between + & -.

Ground was wrinkled up, Pos was good except for small burn through.

That issue is identified, but Motorguide won't work now when correctly wired.

Any ideas on remedy for it? Thanks.

[mxmike]

Check voltage with multi meter at plug. Then turn foot peddle upside down and trace voltage at main power switch and foot peddle button connectors..

[billnorman1]

Your symptoms point to loose connections as the initial cause. With a new plug, you must avoid loose connections or it will repeat. If you have burned a wire/connection interface the wire itself may be damaged to the point it will need to be cut back until you get to an area that is not burned and the copper is still bright. Low voltage usually won't hurt the trolling motor, people run their batteries to the point of extinction and the T/M still works.

[billnorman1]

Check voltage with multi meter at plug. Then turn foot peddle upside down and trace voltage at main power switch and foot peddle button connectors..

Always make final voltage tests with the motor running because no-load readings may not be there with the motor on.

[JohnM64]

Your symptoms point to loose connections as the initial cause. With a new plug, you must avoid loose connections or it will repeat. If you have burned a wire/connection interface the wire itself may be damaged to the point it will need to be cut back until you get to an area that is not burned and the copper is still bright. Low voltage usually won't hurt the trolling motor, people run their batteries to the point of extinction and the T/M still works.

No loose connections, but perhaps too tight.

The insulation was burned through the jackets at contact point of the strain relief in the plug. I believe the strain relief compression stressed and weakened the jacket, and then burned through when it got hot, over time.

I've got power at the receptacle, never tripped breakers, but TM is dead. As recommended, I will start tracing and following power to see where it stops on the TM.

[06x6spdGTO]

Open up 30A Marinco plug, and see the ground wire insulation a bit fried - it appears the strain relief "strained" the insulation to help it melt though for a direct short between + & -.

Ground was wrinkled up, Pos was good except for small burn through.

That issue is identified, but Motorguide won't work now when correctly wired.

Any ideas on remedy for it? Thanks.

That plug is rated at 30amps... Tour 82 pulls up to 54amps worst case, normal operational amps at max thrust in calm conditions with a decent propeller is around 40-44amps.

I would change to a better Marinco 70 Amp plug

[JohnM64]

That plug is rated at 30amps... Tour 82 pulls up to 54amps worst case, normal operational amps at max thrust in calm conditions with a decent propeller is around 40-44amps.

I would change to a better Marinco 70 Amp plug

Thanks- I ordered the Marinco 70 A plug and receptacle yesterday. The 30A was OEM.