I really need help with this, 1990 Motorguide Brute 665 not working right

[waterinthefuel]

I bought an old bass boat and everything on it works good enough except this trolling motor. It has one of those foots that screws to the floor and simply has an on/off switch, a variator in the middle, and a high speed bypass switch. Steering is done with a pole screwed to the trolling motor under the head.

Well, when I got the boat I got it working fine after fiddling with everything and just getting everything moving again. I drag the boat 30 miles to the ramp and now it only goes on high speed bypass. However, if I move the foot around by unscrewing it off the floor, sometimes I can get the variator to work properly. But when it doesn't work, I just hear clicking in the head. I took the top off and the relay is what's clicking, but everything looks fine. No corrosion, loose wires, etc. Same for the switches on the foot. I also did notice that the fwd/reverse switch doesn't work, it only goes in forward. I'll diagnose that later, but right now I'm worried about the variator in the foot. I've never seen one like that. Can someone help me out? Could this be a grounding problem for something? I'm so lost, I've never had a trolling motor like this before.

 

[gm280]

I am assuming by "variator" you mean a variable speed ability. And that is probably a PWM circuit that accomplish that ability. Before getting too involve, check the variable/by pass switch to make certain it id still working. I suspect you will see that that switch if not switching to the variable speed circuit... But that is just a guess not being there and testing it myself...

 

[waterinthefuel]

Ok I think I may have found the problems. And there are more than 1.

I found a broken tab on the high speed bypass switch. This causes the trolling motor to act up when you move the foot around. Not sure if it can be repaired, looks like it might have to be replaced.

The second problem was the clicking. That's the relay. Well, it worked at the house but not at the ramp. The only difference is I had chargers on the batteries at the house. It just dawned on me.....the clicking is the relay. Just like when you are in your car and you turn the key and it goes click click, that's due to low voltage. Well, I know there is one bad battery in the boat out of the two for the trolling motor. Well, I put the battery charger on that battery, I hit the on switch and the trolling motor fired right up. I de-activated the high speed bypass and the potientiometer worked perfectly, the speed varied beautifully. But, the only way it works right is if I hold that connector with my finger while I'm playing with the variable speed knob.

So it appears there was nothing wrong with it to begin with and the reason I could periodically get it to work was when I was charging one or both batteries. I just never put two and two together. That gave the system enough juice to work. But when I got to the landing, the one bad battery was bad enough that the trolling motor wouldn't work right.