I'm trying to figure out what the problem is with this Big Joe (serial#335516) that it only has 3rd speed. I think it's the resistor but I'm not sure. When you turn the handle for 1st speed the contacts engage and all for poles on the motor have 24.6 volts and the same goes for 2nd speed. At the top of the resistor I have 24.6 volts and it drops as I go down the resistor to the middle connection where the negative and the 3rd speed cable going to the 3rd speed contact connect. Going down the resistor after the negative cable it shows 0.4 to 0 volts. Any suggestions or help would be greatly appreciated.