My 2009 Yamaha YDRE dropped to 15 MPH then died. I cleaned corroded throttle stop switch, tightened all bat, solenoid & controller connections. Cart ran again, but only 15mph- normal speed is 19.9 - 22. Cart then would not run again. Throttle position sensor resistances tested out of spec and I have part ordered. Don't have special cable needed to test the motor speed sensor voltages so I pulled the sensor. It looks absolutely clean and the magnet also looks good. Any suggestions for finding the problem while I'm awaiting the TPS in case the TPS doesn't do it?