Trolling motor wiring question

[Starkonian]

I have a trolling motor which does not have variable speed control. So, I'm running the intake voltage through a PWM, variable speed controller. Has worked great for the last two years. I just bought a new one which has a reverse switch. Will it do any damage to the motor reversing the power supply via the switch? I'd mostly use it to back out of weed beds etc. without having to rotate the tiller control all the way to reverse. I believe most/all electric motors run fine if the power leads are reversed but thought I'd through it out here for comments. I believe when you rotate the tiller from forward to reverse the power is just switched or reversed anyways. Thank you.

 

[dwco5051]

Just an opinion but I would guess you could run one in reverse. I have several transom mount electric trolling motors that have both forward and reverse. My bow mount motors don't but they are foot pedal controlled and can turn 360 degrees. I know one of my transom mount motors has 5 speeds forwards and only three in reverse but I think that is just because of the inefficiency of the prop spinning backwards doesn't justify more selections.

 

[gm280]

IF, and that is a big IF, your trolling motor has ZERO circuits inside, then yes you can reverse the power leads and it will run backwards. However, since you stated that you are using a PWM circuit, you have to either remove that circuit out of the power leads to the motor, or reversing the power leads will most likely destroy the PWM circuit.

It really depends on how that PWM circuit is made. But I wouldn't try it to see unless you have more money to replace it if it isn't wired to allow reverse power connections.

Your could use a DPDT toggle switch setup to either use the PWM input to the Trolling motor, or flip the toggle switch and use the reverse power lead set up. That way you isolate the PWM circuit when it is in the reverse switch setting.

Just use the two center terminals in that DPDT switch connected to the trolling motor and use one set of the two outside terminals to the PWM circuit and the two outside terminals to the Reverse power lead setup for the other option. Should work that way.

 

[fishrdan]

I just bought a new one which has a reverse switch. Will it do any damage to the motor reversing the power supply via the switch?

New one.... what? PWM controller or trolling motor?

If you're using an old style speed coil 5/3 speed trolling motor, the 5/3 switch reverses the + and - in reverse, so a PWM controller that reverses the voltage will work.

If the trolling motor has the reverse switch, that will work also, but I wouldn't flipping F-R-F-R on the trolling motor switch with the PWM controller applying power to the motor, it may not like the reverse voltage it may get if the motor is still turning... Also, omit the speed coil connections on the switch (if they are still connected, or you'll be wasting power through the speed coils.

Out of curiosity, what PWM controller are you using?

 

[Starkonian]

Having shortened the shaft originally, I had the head off of the motor. The motor is a basic 5 forward and 3 reverse single switch motor. I've been running the battery into the PWM and out to the motor. The new PWM I'm getting is similar to the old one I have now but the new one has a reverse toggle switch. I set the motor on high, speed 5, and control speed with the potentiometer. I have the PWM mounted in a box on a transom board I constructed. I already figured before switching direction with the reverse toggle switch I'd power down the pentiometer input to avoid slamming the internals and causing wear and tear. I'd did get a response to this question form Minkota, here's what they said, "It would depend on what type of motor. For a 5 speed motor it will run in reverse of the usual functions, however it can cause damage if left reversed and is run on high speeds for prolonged periods of time." I don't why they say this, there is no warning in the instruction manual advising not to run the motor in reverse as they describe. I'm going to ask them to elaborate. Anyways, here is the new PWM I purchased and also here is the trolling motor. I have the 55lb thrust model. It's been a very reliable motor and replaces a Minkota C2 30 motor I had and the head internals look fairly identical by design. Btw...I'm not planning to run the motor full speed for long period of time via the PWM reverse switch anyways. Just short bursts for course correction etc.

 

[Starkonian]

So I received a clarification from Minkota, "Well I should specify, we do not recommend the motors as a primary propulsion system, so if it is run at high speeds for a prolonged period of time either way, it can cause the motor to burn out faster." It seems the concern is heat buildup from long term running and unrelated to the reverse polarity question I raised. I've heard this before from them btw, accordingly I don't run trolling motors full speed form more than 20 minutes without a cool down period. That said, they also told me previously their motors with the built in variable speed control does not have this restriction warning. So, By adding the PWM my motor has the variable speed control their other motors have, perhaps better quality to boot. I don't know what to think of their advice...

 

[iam2sam]

So I received a clarification from Minkota... I don't know what to think of their advice...

So, how has this set-up worked for you after nearly a year? How much whine/hum do you hear (if any)? I want to use a PWM controller with a Watersnake 24 lb. motor and a 75 AH AGM battery on a Grumman 13' canoe. I would be making the same saltwater creek run (~4 mile round trip) regularly, and I'm hopeful that if I watch my tides, I can make the trip with nearly no paddling. I may try to add a 100W PV panel later (I only run solo, so I do have space to mount it): In theory, that would allow me to run all day at half-power in full sun with no battery consumption. Of course, Murphy is a great at debunking theory, and I don't intend to add any complications unless they prove to be necessary... FWIW for others interested, the original eBay link cited no longer works, but a search on the item description will easily turn up an identical offer.