Trolling motor works in reverse only

Question
I just bought a used boat a few weeks ago that came with a trolling motor.  I bought a new marine battery to go with it.  I took it out 2-3 times and the trolling motor worked great.  It has 4 speeds in forwards and 2 in reverse.  The last time I took it out, I trolled around for 2-3 hours.  I then put it in high gear for the first time as I headed back to the dock.  I shut it off for about 10 seconds and tried to go a little bit farther, however it would not troll any more.  I then switched it to reverse, and reverse still works.  I have tried all of the speeds in forwards and cannot seem to get it to work.  Do you have any ideas on what I can check.

Answer
JR; If the motor is a relatively new motor I would not touch it until I had talked to the company that made it.  If you take anything apart it would void any warranty

If, however, it is not a new motor I would start by checking the switch in the foot control if it has one or the head if it is not foot controlled.  Something like this is often a bad connection.  If you can not visually find any problem use a voltmeter (you can buy one for a few bucks most anyplace and it is a handy thing to have around.)  Start at the switch and turn the motor to forward and test the lead going to each of the speed coils.  Since it is all speeds it is likely something keeping power from getting to the motor.  If you ran it for a long time a wire may have gotten hot and burned in two.  If there is no power coming out of the switch to the coils it must be a bad switch on the forward contacts.  If you do have power coming from the switch going to the motor the problem is likely in the motor itself.  Unless you are familiar with DC motors I would not mess with it but take it to a repair shop.  I often have repaired my own but then I was an electrician years ago and know enough about motors to do most repairs.  But if there is anything electronic in it I don't touch it.

Don't run the motor out of water more than a few seconds at a time while testing it as this will overheat it for sure.  It depends on the water to keep it cool.

If you are lucky and it is just a loose or burned wire you can repair it yourself.  Make sure you clean the wire with sandpaper (not emery paper) before reconnecting it.

I hope this has been of some help.  There are many different ways  of controlling the speed of a trolling motor that I can not tell you specifically more than I have.  

Thanks for calling on me for your question.  If I can be of further help please call on me.

I am
Jack AL. Gaiter  (Backroom)
Lake Seminole, Georgia