Motorguide quits

[RoughFishAssassins]

Hello,
I have 2 motorguide 82lb thrust trollers that I experiance the same problem with. THey both cut out/shut off after a period of running in the higher range of speed. There are some times that you can feel the motors slowly loosing power and within minutes full power is not much more than the slowest speed. THey are identical units with identical problems. I was told that the problem was the module board in the motor, well I replaced it in one of them and made no difference.
I am running power to the troller via either 4 or 2 guage wire not exactly sure off the top of my head. and that is only about 6 feet of wiring. I have a manual resert 50 or 60 amp breaker in line also. This set up is on a bowfishing boat and we run an Iota 27-40 converter to maintain full power all night long. When this problem happens I am able to quickly check the voltage and even monitor the voltage until it happens and the voltage maintains 23-25 volts.
If the motor is left alone for a couple minutes it will come back on, sometimes lasting a couple minutes till the next time and other times it lasts 30 minutes plus. I was also told about a sensor of some sort that is in the motor to prevent it from overheating. Is there something in the motor like this. There really isn't alot in the motor, basically the module board and the brush card with a couple relay looking things on it. My thoughts are that if there is such a thing as a heat sensor thing that it must be on this board but why on both motors? Both of the motors I bought second hand and never seen them run before purchasing them. One of them I didnt have a problem with for a while. I have contacted motorguide about this and they tellme to take it to a certified mechanic, but I cant justify spending $80 per hour on these guys. So I ask for your help, someone else out there must have had or is having this same problem.

 

[RoughFishAssassins]

Re: Motorguide quits

No onehas any problems like this before? I am the only one?

 

[fucawi]

Re: Motorguide quits

personally I would be looking to run it in a swimming pool or large barrel so you can see whats going on in comfort.....Why not power it direct to the brushes once it cuts out and see if it goes good again...this will rule out or in the electronics ..usually the motor is water cooled ..dont run it out of water it burns up the shaft seal ..sounds to me like an overheat problem in the controller that is shutting down the controller....

 

[fishrdan]

Re: Motorguide quits

If you think it's a control board, pop the cover off anf run it until it acts up, then hit the board with canned air to quickly cool it down, see if the problem goes away with cooling the board(s).

I'd also check the breaker and see exactly what the rating is. That 80# motor probably pulls around 50-60 amps @24V full power, at least that's what the Minn Kota 80# Vector spec sheet shows,,, 56amps@24V.

 

[RoughFishAssassins]

Re: Motorguide quits

Well the problem with trying to cool the board down is, all the electronics ar in the motor, nothing is in the handle/head. only the incoming lines, the switch which has been bypassed already, and the variable speed pot.
As for putting power directly to the brushes when it first cuts out, well that would be a trick, by the time I could get it open it would be running fine again, well not sure about that but this isn't something that opens really fast. Fucawi, do you think that it could have some sort of heat protection crap in it that is going bad? I am just at a loss and can't afford to have a mechanic look at it.

 

[Barnacle_Bill]

Re: Motorguide quits

Temporally bypass the circuit breaker and try it again.

 

[cyclops2]

Re: Motorguide quits

If the battery volts hold constant.

Then go after a loose connection in the power plugs or splices in the wires in the boat or footpedal box . Both motors is a factory reject of a loose connection in your boat.

Did the motors do this from day 1 ?

 

[RoughFishAssassins]

Re: Motorguide quits

Bypassing the circuit breaker has already been done with no change.

I got both motors used so I couldnt say for sure, but I know the one didnt do it, or atleast I dont remember it doing it the first couple times that I used it. The power plugs are anderson plugs with the wire soldered into the tips, and one of the motors goes directly from the plug tight to the connections in the motor without any splices.
These motors are tiller types, no foot pedals here.

I really appreciate thehelp guys, this site is full of help. THANK YOU!!

 

[fucawi]

Re: Motorguide quits

Electronics in the motor head ..how stupid can they get ....any way you can get the electronics up top ? wires down the shaft to the brushes etc....The MOSFETS in the controller will have temperature shut down built in ...

 

[cyclops2]

Re: Motorguide quits

They are NOT stupid.

Guess who will probably wind up using a factory repair shop. Protect the service places !!!!!

The electronics in the motor are a SURE SIGN that they are pushing the units WAY WAY past what should be the safe thrust levels. CRAP company now.

 

[fucawi]

Re: Motorguide quits

well this guy has not got problems with the motor i guess probably the controller and its in there to keep cool..is it bolted to the outer case ...cool water .....

 

[John_S]

Re: Motorguide quits

Do you have the model number or already have found a link to online schematics?

 

[RoughFishAssassins]

Re: Motorguide quits

Sorry, but there is no way to get any of the electronice to the top side, there is a bunch integrated right into the brush card and the other module is practically molded into the motor also, bolted from the back side. Like I said before, I already replaced the module assembly, which as far as I could tell replaces the mother board. I hate the thought of just throwing money into this but maybe I should try to replace the brush card with all the crap that is on there? I look at it this way, it cost about the same as a mechanic to look at it and tell me what is wrong, but really what else could be in this thing, the only parts that have anything to do with electricity is the module assembly, the brush card, and the variable speed pot. I have attached pics of what I have. Those are pics of the backside of the brush card, the module assembly, and the other side of the brush card. Please let me know what you think.

 

[RoughFishAssassins]

Re: Motorguide quits

The motor is a 2003 Motorguide model 9CT42KQAF

 

[fucawi]

Re: Motorguide quits

well the two boxes are the reversing relays ... are you sure its not a dodgy pot on the speed controller thats giving problems though I still think its the MOSFETS..

if it was mine the two thick wires would go straight to the brushes and do al the controll above the water line ..I bet a mechanic would just bin all the brushgear/circuit board and control pot and fit all new .....$$$$$$$

 

[RoughFishAssassins]

Re: Motorguide quits

Fucawi, you think it could be the pot causing the problems? is there a way that I could diagnose it, I have a multimeter handy to do so. Also, you mentioned reversing relays, that just reminded me that the reverse doesnt work on one of them for sure either, never was a big deal do to the fact we would just spin the motor around for reverse, not sure if that would make a difference in anything or not. I really appreciate your help with this.

 

[cyclops2]

Re: Motorguide quits

We are DEFINATELY getting a loose connection heating up, Not found. Both motors are pulling too much current due to use & age. Or possibly if those black boxes are the F & R relays, The contacts are arcing from end of their lives. The motors could have bad heat sensors on them IF so equipped.

I vote relay contacts wearing out. If they are cheap enough. BUY 2 NEW ONES. ONLY if they are easy to change. Look at the Printed Circuit board where the relays are soldered. You may see discoloration or some Solder melting & moving downward due to gravity.

Also check the amount of Solder holding ALL the heavy wires in place.

 

[RoughFishAssassins]

Re: Motorguide quits

Well the relays can be changed but are only available on a new brush card! which is no big deal to replace just dont want to keep buying parts that dont need to be replaced.

 

[cyclops2]

Re: Motorguide quits

Post back on what the real problem is when you find it.

Should be others getting close to your problem.

 

[RoughFishAssassins]

Re: Motorguide quits

I most definetly will post what the cure was, although I am afraid that a cure wont come soon enough, tomorrow night is the last time we are taking the boat out for the year, it is going into storage until april this weekend. Just hoping to get some ideas and possibly fix it before hand, or atleast being able to test some things out.