Voltage tests fine, but only single speed

[Moondog317]

Here's one for you. I have an electric boat.The perfect cocktail cruiser. The drive is nothing more than a 36 v. golf cart. No speed control, just a 5 position {R2,R1,N,F,F2} snap switch and a couple diodes wired in. Everything worked fine until a magnet got loose in the moter and made a grinding sound. Pulled the motor out and had the magnet repaired. Put it back in and now only 1 speed reguardless of swith position. I realized today, that I get 17+ volts on low and 34 on high, either direction with the motor leads disconnected, but only 17 at the motor with the leads hooked up. I checked all four brushes and continuity from the terminals to the brushes and all looks good.
Motor is a Peerless 36 v.
I'm puzzled, any ideas out there?

[Moondog317]

What no ideas here?

[Justin_NY]

Did you figure it out?

That isn't the true schematic. That's just your main wiring diagram for the batteries showing the polarity protection in the control box. You need a resistor, scr circuit, or transistor in there to change the voltage. But if you're seeing the voltage change I'd say you have a seized bearing in the motor or have some sort of alignment issue when you re-installed it. Worst case, the motor shorted and damaged the control circuit when it failed.