Maxxum 80 sporadic off and on

[cxp138]

My Maxxum 80# works perfectly in the driveway of course but goes off and on on the water with no noticeable pattern. When it goes off I checked to see if the prop was in a dead spot on the armature but couldn't identify any pattern. Seems like when I pull it out of the water i can get it to spin again by removing the load, but even this doesn't happen consistently enough that i can call it the definitive cause. I checked voltage 25.1 at the plug. 24.8 in the foot pedal. 24.8 in the head when i disconnect the wires from their connection to the prop. Once i connect it to the prop and turn it on continuous the prop spins and voltage drops to 17.8. I'm assuming due to the voltage drop as the prop is now turning? I've changed every connection in the head and foot pedal but i'm still stumped If one of the consistently helpful members here can't help me solve this by the weekend i'm going to have to break down and buy a new one that was definitely not in the budget for this spring.

[Jonestrollingmotor]

That is too much of a voltage drop. The way I'm reading, this is a voltage reading without it being in the water under a load. From the voltage given, I suspect either a bad battery in the mix or some dirty/bad connections. Doesn't sound like a trolling motor problem at this point and I don't think a new trolling motor will change the battery/wiring problem suspected.
John

[cxp138]

Thanks John! Very interesting. Your assumption is correct. Voltage drops to 17.8 when running in my driveway under no water load. Is there an easy way to analyze the health of the batteries aside from confirming the voltage is correct?

[Jonestrollingmotor]

Make sure they're up before going fishing. After a couple of hours they'll probably start acting up and you can take a voltage reading of both batteries. They should be close to the same, however if a bad one then it will be lower voltage than the other. I'm leaning more towards connections/wiring.
John

[cxp138]

Would it have anything to do with having AGM batteries connected to the standard pro series Ranger on board charger? Doesn't have a switch for AGM? I will take both batteries to the auto parts shop to be tested. Like I said I snipped off and replaced every connector in the trolling motor so that would be a wild goose chase all over again. Thanks as always for your help.

[billnorman1]

I think it wouldn't hurt to get a silver marker pen and put a stripe on your motor and prop and see if the prop stops in the same place always. You indeed have low voltage but the motor should still run I think.
You should also remove the prop to see if there is any fishing line behind it.
I'm tempted to suggest removing a bolt to see if there is water in the housing.

[cxp138]

Thanks Bill. Prop has been removed due to all the testing i've been doing in my driveway for safety. Batteries say fully charged one is at 12.6 the other at 12.9. Runs flawlessly in driveway. I'm away for the holiday weekend but when I return i'll have the batteries health tested at the local autozone. At this point i'm willing to try anything. I will remove a bolt and even pull out the armature if you think that will tell me something. Thanks for your input. John seems to think the problem is in my power system not the motor so i'm trying to eliminate all possibilities on this side. I do have the same exact motor on a tin boat that I could swap and try but was hoping to save the hassle of removing them both. The bolts are a pita to get to. Thanks again to everyone for their feedback.

[billnorman1]

Well if it's a foot control motor maybe you could just swap the motor/shaft assembly. The volts are pretty low, that's why I suggested you look for drag on the shaft. Check the tightness of the screws in the back of the male connector. Since it stops, it could be a circuit breaker issue. This is if you use the Marinco plug.
I think one should check inside the motor as a last resort.

[cxp138]

Just had both batteries tested at autozone. One 12.72 with 839 measured CCA rated for 800. The other 12.63 with 878 CCA. No water in the bullet. 25.3V to the head which means full voltage making it through the plug and foot pedal. My plug has 4 prongs and the breaker is in the battery compartment at the stern. Looks like minn kota won this battle. I'll be pulling it off this week and switching it out with the maxxum on my tin boat. Of course the maxxum doesn't have any easy way to switch like for like aside from taking the bow plates off and getting under there to take the whole dang thing off. Question now is how far across my driveway will i be able to throw this thing once I remove it

[ethosb]

I had a similar behavior in my Maxxum Pro TM this weekend with it sporadically coming off and on. Sometimes it would stay on once I pulled my foot off the pedal. My issue was a bad spring underneath the foot control button. Took it apart on the water and found that the spring had broken. The foot pedal button is magnetic and was getting improper input.

[cxp138]

Thanks for the feedback ethosb. I had that all apart and mine has the same symptoms even when I put it on Continuous, so i ruled out the button. I definitely have a power issue here just can't seem to figure it out, and i'm at the point of frustration where smashing it all over my driveway will give me great satisfaction. One last connection to change for me. I snipped off the red wire connection inside the head. Seems a low awg wire. Is this acceptable to use to splice it or will it add to my problems? If not what is the acceptable way to splice this wire back.
https://www.zoro.com/burndy-mechancl...CABEgK6NvD_BwE
Any other ideas on how i can test and troubleshoot my power system would be greatly appreciated. I currently only have voltmeters but if i need to buy an amp meter i can do so.

[cxp138]

More to the mystery. Checking voltage in the head shows 3.7V at lowest speed. 23.4 at highest speed??

[billnorman1]

Change your current limiter, they are cheap. If the problem persists, try something else. They are cheap, and this eliminates a potential intermittent issue. Your voltage at full speed seems quite good, but there isn't much load in air.

[cxp138]

Current limiter is located where?

[Jonestrollingmotor]

Current limiter is located where?

He's talking about the breaker/fuse. some info you need to know. When you're checking voltage at the plug, it is the same as checking at the batteries except you may have some voltage drop due to connections, hence you're going to see close to battery voltage when checked at the plug. To check for a true voltage drop like it seems you have at the head of the trollingmotor, you have to check it while under a load, that is the trolling motor turned on. Best way to check is to turn the footpedal over, remove the base plate and determine which wires are coming from the battery to the control board. turn the trolling motor on constant and check the voltage at that point. If it still drops as much as it does in the head, you have a connection problem in the boat -- it ain't the trolling motor. If you get battery voltage when you turn the trolling motor on and check at the control board, then you have a trolling motor issue and you should check the output voltage at the board. The lower you turn the speed control, them more the voltage will reduce. On high, it should be close to the battery input voltage. If it doesn't do that, you have a board issue. I'm still guessing on a connection issue, either on the boat or at the control board.
John

[Bradrodfish]

John is correct. I suspect as he said. either a loose or corroded connection.

[cxp138]

Thanks guys. I will check this again tonight, but as I mentioned in earlier posts. I've checked the voltage while the TM was turned off at the batteries, then up at the plug, then in the foot pedal, and then in the head. All showed 25+V. When i turned the trolling motor on and checked in the head I was getting 3V at the lowest speed and 24 at the highest. I've not yet checked the voltage in the footpedal while the motor was turned on, but if it showed 24 in the head while ON wouldn't that mean the same would have to be true in the footpedal which is earlier in the circuit? If not i'll definitely test it. I have one more predicament. The negative cable in the head connector looked a touch corroded so I cut it off. Now i have what appears to be a 6-8 awg cable that I need to splice. What would be the best way to do this in order to not add to the problem. I don't have any connectors on hand large enough, and all I have is an aluminum copper block that I posted a link to above. thanks again for all your help.

[Jonestrollingmotor]

Thanks guys. I will check this again tonight, but as I mentioned in earlier posts. I've checked the voltage while the TM was turned off at the batteries, then up at the plug, then in the foot pedal, and then in the head. All showed 25+V. When i turned the trolling motor on and checked in the head I was getting 3V at the lowest speed and 24 at the highest.

When you loaded (turned it on) you had a voltage drop of apx 1.5 - 2V. This is coming out of the control board which is probably going mean that the input on the control board is going to fall also, which indicates a bad connection, corrosion, bad breaker or other problem in the boat side wiring.

I've not yet checked the voltage in the footpedal while the motor was turned on, but if it showed 24 in the head while ON wouldn't that mean the same would have to be true in the footpedal which is earlier in the circuit? If not i'll definitely test it.

24V is too low, again, that means a voltage drop either from the control board to head or on the input of the control board when the circuit is under a load.

I have one more predicament. The negative cable in the head connector looked a touch corroded so I cut it off. Now i have what appears to be a 6-8 awg cable that I need to splice. What would be the best way to do this in order to not add to the problem. I don't have any connectors on hand large enough, and all I have is an aluminum copper block that I posted a link to above. thanks again for all your help.

That wiring in the head is 10ga. MinnKota uses slip on spade connections and you can purchase both male and female at any auto parts store. Will have yellow covers. Make sure you have quality crimpers to make the crimp a good connection.

[cxp138]

Thank you sir! I will go at it again. I haven't checked the Ranger On/Off switch back in the battery storage area. I'm assuming there is a breaker inside it.

[Jonestrollingmotor]

The Ranger could have as many as 3 different power switches in the bilge area. There is an on/off switch for both the power side coming off the cranking battery feeding the dash that contains a breaker, there is one for the trolling motor side that has a breaker in it, and there could be a battery selector switch that allows you to choose battery 1, battery 2 or both. There is no breaker in that switch. This is the switch that I'm referring to in my wiring setup.
John