I have a 24v Minn-Kota Ultrex.  The 3-pronged plug has become loose and sometimes the motor shuts off.  I noticed the o-ring was missing so I replaced it.   Didn't help.  I tried a slightly thicker o-ring and the plug wouldn't fit.  Any thoughts?

It sounds like the connector is loose. Those pins should fit tightly and snuggly into their connecting holes.

 

Bad or loose connections can cause increased resistance across loose connections and tend to heat up.

 

Sounds like a new connector is in your future. Replace and keep on keeping on.

 

 

2 minutes ago, FloridaFishinFool said:

O rings don't make electrical connections.

 

 

The o-ring makes the plug fit snugly in the receptacle.

 

I will probably replace both male and female connections.  Seems simple enough.

Makes the plug fit snugly. Not the electrical connections. If those are bad you could glue it in there and still have problems.

 

It is those connections that need to be snug and tight. Without seeing it I tend to think the O ring is to keep water out, not make electrical connections is my point.

 

Either way you slice it, it appears a new connector may be your best solution all the way around.

21 hours ago, RobA said:

 

 

I will probably replace both male and female connections.  Seems simple enough.

 

Both would be best.

The plug (with pin / blades ) and 1 ground pin is a NEMA 5 standard 15 amp.

You can bend ( splay) the blade pins outward slightly to improve contact retention. Most boats use 3 contact twists lock plug and receptacle to eleminate lose contact.

If the plug has 70 amp round pins you need to replace the plug, receptacle w/ sockets,  sound be OK.

Tom

Thanks Tom.  I was thinking of doing that as it's something I have done with household plugs.  The plug I have is the twist lock and not the pin type.

Switch to Anderson Connections.  ??

Switched to Trac connectors from BPS on boat and charger.

I’d go ahead and replace the plug and receptacle. Cheap insurance from a meltdown.

 

I’ve got the Camco/Trac on mine, and replace them every couple of years to stay ahead of corrosion/resistance (this is also about the lifespan of the little bulkhead/bushing). 

On 9/10/2025 at 8:10 AM, Lottabass said:

Switched to Trac connectors from BPS on boat and charger.

Do this, these plugs are great, and create a solid connection that doesn’t wear out from repeated use. 

I wound up splaying each of the 3 blades outward just a bit.   Seems to have done the trick.  The connection is much tighter than before and doesn't wobble at all.  Easy fix.  Thanks Tom.

Do they make the Trac connector in a 3-pin configuration?

 

I don’t believe so. I’ve got my leads siamesed into the one connector.

My trolling motor is hardwired. No plug.

I use a Minn Kota MK-26 plug to get power through the "bulkhead". That plug ain't playing around.