Motorguide 71 - lost speedcontrol

[rick56]

My Motorguide footcontrolled trolling motor just crapped out on me and made me cut my fishing trip short. I had pulled up close to the bank to help my fishing partner get unhung, and as I pulled out, the prop was cutting through the dead weed stalks, when it quit. It was in the lowest setting 1 (5 speed 24 v) so I cranked it up to 2 - no response - 3 & it kicked on. I then turned to 4 and it quit - 5 & and it kicked on again. When I returned it to 1 it ran but made a curious whine, 2 - the same, 3 - ran fine, 4 nothing, 5 fine. Later on 1,2 & 3 all produced only the #3's rpm. No 4. 5 still ran perfect. Took it out on the lake here at home and after running for a short time as described above I lost all but #5.
Has anyone every suffered through this or have any clues? I checked my switch connections annd they are intact. Removed head cover and all connections are good there. My next move is to disconnect the leads from the rheostat and check for burnt switches but I'm thinking the windings may be shot. I purchased the thing, new, on Ebay so warranty is out of the picture. I'm a master electrician and know how to check everything but thought someone might save me some time.

 

[tashasdaddy]

Re: Motorguide 71 - lost speedcontrol

http://www.trollingmotorparts.com/

 

[rick56]

Re: Motorguide 71 - lost speedcontrol

Thanks! Wiring diagram was available at that site.

 

[Silvertip]

Re: Motorguide 71 - lost speedcontrol

If you have switch positions 1 through 5 you don't have a rheostat, you have a five speed switch. Setting #5 is direct to the motor and should produce fastest speed. Speeds 1 through 4 work through what are called speed coils or in electronics speak, wire wound resistors. So the net result is, if speed 5 works normally, but 1 though 4 are either intermittent or don't work at all, its a speed coil or switch issue. The fact that you stalled the motor with weeds, I suspect you tripped the auto reset circuit breaker (if you have one). You might also pull the prop and check for fish line and/or stringy weed stuff as that can make the motor draw lots of current. Speed coils are located in the motor itself. On a speed coil motor you will find red, black, and four other wires in the head. Disconnect all wires in the head and using an ohm meter, check for continuity between black (ground and all of the other wires except red. If you have continuity, the motor will run on all of those speeds but speed may not be what it used to be. some of the speed coils are connected in a voltage dropping network and may even be connected in parallel for certain speeds. If that's the case, you may have one open coil but the motor still runs. If one or more wires shows open, you definitely have an open coil.

 

[rick56]

Re: Motorguide 71 - lost speedcontrol

Thanks Silvertip! I located the problem after ruling out the 5 speed switch and pulled the lower unit to find the coils fried. I have a 30 ampbreaker that should have tripped before this happened but it must be defective. Anyone know where the coil unit can be purchased for a Motorguide 71 24v?

 

[billieand]

Have the same problem where can I buy this coil or can I repair the one I have

 

[GA_Boater]

Have the same problem where can I buy this coil or can I repair the one I have

billie - This an awfully old thread. Please click on the Forum Help in the sig below about starting your own thread for the best chance at fixing your TM.

Also remember just because your problem seems similar that doesn't mean you do have the same problem without doing some troubleshooting.

Closed.