Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Trolling Motor Connector Overheats and Melts

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Trolling Motor Connector Overheats and Melts
DeepSouthWhaler posted 06-13-2006 09:29 AM ET (US)   Profile for DeepSouthWhaler  
The trolling motor socket and plug on my 18 Dauntless has melted. The trolling motor is 24 volt motor. [What is the current] rating for the wiring and socket on the Dauntless?
Plotman posted 06-13-2006 09:40 AM ET (US)     Profile for Plotman  Send Email to Plotman     
What do you mean it keeps melting? Does that mean you replace it and it melts again?

Does you have to try to use the motor for it to melt, or just plug it in. Whatever the answer, for God's sake, stop. Uh, was this a factory or dealer install? Trace the wiring back to the distribution source and see what you've got.

Voltage isn't what melted that plug, current is. It would seem that you must have a short somewhere...

DeepSouthWhaler posted 06-13-2006 11:12 AM ET (US)     Profile for DeepSouthWhaler    
First the plug melted and I had that replaced. Now the socket has melted. Both times that the melting happened, the motor was being run near full speed for a long period of time.

The socket and all wiring is original from the factory. The socket is located on a panel on the bow. Connected to the socket are two wires, one red and one black. Both wires appear to be 8 gauge. These two wires run together in a narrow conduit that runs to underneath the console. The wires connect directly to the two batteries along with a jumper wire that makes it a 24 volt system. The connections are as follows the black wire is connected to the negative terminal on battery 1, the red wire is connected to the positive terminal on battery 2 and the jumper wire connects the positive terminal on battery 1 to the negative terminal on battery 2.

Should I try a larger wire size?

Chuck Tribolet posted 06-13-2006 11:36 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Does the wire get hot? If not, it's OK. And Look for a size on it. 8 ga. seems big enough, but it would be good to have
the specs on the trolling motor. What make and model trolling motor?

I suspect the problem is resistance at the plug, possibly
from corrosion. The resistance might be between plug and
socket, or were the wires attach to the plug/socket.

Salt water or fresh water?


Bulldog posted 06-13-2006 02:09 PM ET (US)     Profile for Bulldog  Send Email to Bulldog     
The resistance is at the plug/ socket connection , it is what is getting hot and failing. If the connection got hot enough to melt your plug, the socket probably has deteriorated a bit also. I think you had a bad connection between the plug and socket, melting the plug , which you then replaced now the socket has failed,because of the first incident, get another socket. Before replacing the socket take the plug and plug it in , use an ohm meter and see that you have no resistance, before reinstalling the socket. Make sure your socket is rated for the amps the motor is pulling, using number 8 wire but going through say a 30 amp plug,makes the plug essentially a fuseable link and will always fail under long full load condtions. Checking the connection by hand at times is a good practice while using the trolling motor....Jack
DeepSouthWhaler posted 06-13-2006 02:36 PM ET (US)     Profile for DeepSouthWhaler    
I already have a replacement socket from Boston Whaler. I have a call in to see what the rating is. The wiring looks good with very minor surface corrosion. I don't have an ohm meter and I would not know how to use it if I had one. I plan on checking the wiring size and the amp draw tonight. The boat is used exclusively in saltwater. The motor is a Motorguide Great White 74lb thrust model. In is the same year as the boat (1999) From what everybody tells me, trolling motors around here usually don't last more than 5 years.

thanks, Kevin

Bulldog posted 06-13-2006 04:52 PM ET (US)     Profile for Bulldog  Send Email to Bulldog     
Skip the Ohm meter thing then, but a little surface corrosion can go a long way in causing your problem. After checking your ratings clean that wiring up to a high shine and make tight connections , you will probably be fine then...Jack
Chuck Tribolet posted 06-13-2006 08:26 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
From the Motorguide website, it looks like your motor will
pull about 20 amps. They recommend 6 ga wire.


jimh posted 06-13-2006 11:01 PM ET (US)     Profile for jimh  Send Email to jimh     
When substantial current flows, such as occurs with trolling motors, even a small resistance can generate significant heat. When this occurs at a point-contact such as in a connector, the heat is confined to a small area and can eventually raise the temperature quite high above ambient.

Keeping the contacts clean and free from corrosion will prevent them from having too much resistance and creating this excess heat.

DeepSouthWhaler posted 06-14-2006 11:01 AM ET (US)     Profile for DeepSouthWhaler    
I disconnected everything last night and pulled the wire. I think that I found the problem. The wire is 6 ga. only for a few feet past the socket. A splice was made with 10 AWG wire for the remainder of the run to the batteries. Also, there was no in-line circuit breaker. I am just going to run all new 6 AWG marine wire, put on new ring connectors with the heat shrink tubing, add an in-line circuit breaker and install a new socket. Hopefully this should do it.
Bulldog posted 06-14-2006 11:10 AM ET (US)     Profile for Bulldog  Send Email to Bulldog     
Sounds like a plan, you should be set, perhaps even getting better performance out of the trolling motor because of reducing the voltage drop!.....Jack
jimh posted 06-18-2006 09:23 AM ET (US)     Profile for jimh  Send Email to jimh     
Having wiring that was more resistive would tend to make the connector less likely to overheat. As the resistance in the wire increases, the total current flow would tend to decrease. This would tend to decrease the current flow through the connector, and that will reduce the heating at the connector.

On second thought, there may be a relationship. The smaller wire may become warm, and it may conduct some heat to the connector.

A 10-AWG cable can carry 30-amperes with minimal temperature rise. How much current does the trolling motor use?

davej14 posted 06-18-2006 11:07 AM ET (US)     Profile for davej14  Send Email to davej14     
Jimh is right. Although running larger wire directly from the battery to the socket is a good idea, it will not be the solution to you socket and plug melting. It may actually make it worse. You either have an under rated socket and plug combination for your motor or a corrosion problem with the contacts or connections.

Was this a factory install? I cannot believe that they would have spliced the socket wires to a smaller wire gage within the wiring tunnel. You are fortunate that the plug melted instead of having a fire in the tunnel.

DeepSouthWhaler posted 06-19-2006 12:17 PM ET (US)     Profile for DeepSouthWhaler    
The manual says that the motor draws 20 amps but it says to use a 40 amp circuit breaker. It also recommends 6 gauge wire for any runs longer than 6 feet. The socket used is from the factory. The new socket that I ordered from Boston Whaler is the identical size and brand. They could not give me a rating on this socket. It is the same socket used on the 22 Dauntless. The 22 would require a much larger trolling motor. I am the second owner of this boat. I know that the splice is not from the factory. The wiring under the console was a mess when I got the boat. I have made some improvements, but it really needs to be completed refitted.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.