I isolated the problem by bridging the large posts on the solenoid with a 6 gauge battery cable. The cart then went fine, so I replaced the solenoid and all's well. If the cart has the continuously variable potentiometer (small black box under the accelerator pedal) the manual shows it being tested with a "Calibration Test Module" a piece of equipment I don't think many of us have. If by any chance it has the Multi-step Potentiometer ( largish quarter circle shaped box behind battery #5. then it can be tested with a multimeter. I am a bit reluctant to describe my method of bridging the solenoid because of the danger of batteries and sparks, but if you are prepared to accept the potential danger here it is. Disconnect the positive terminal of battery #1 then the negative terminal on battery #6, place the fwd/reverse switch in reverse and discharge the buzzer capacitor. Move switch back to neutral. Turn off the ignition switch. Raise one of the rear wheels off the ground, bridge the large posts of the solenoid with 6 gauge wire. Reconnect #1 positive battery cable then #6 negative battery cable. BEWARE YOU ARE NOW IN THE DANGER ZONE. WHEN CONNECTING THE NEGATIVE CABLE TO THE BATTERY THERE WILL BE A SPARK AND A SHARP BANG. I have done it many times and it still startles me. Make sure all battery caps are secure and the area well ventilated. Battery fumes have been known to ignite and batteries explode. Turn on the ignition switch, turn the fwd/reverse switch to fwd, press the accelerator and the wheel that's raised off the ground should start turning. Release and depress the accelerator a few times to make sure the results are consistent, if they are replace the solenoid, if not then its not the solenoid that's the problem. Maybe someone else has a better plan than mine. Good luck