We have an EZGO 36 volt PDS golf cart. Put in new batteries,fully charged,replaced the ITS,solenoid & Curtis controller. Then took the motor off,checked the brushes [they were good] & blew the dust out. We hooked up a voltmeter to it & have 36 volts when we drive it until we stop for a minute or so. Then it drives at 1/2 speed & shows 18 volts. Switching the F&R switch from forward to reverse a few times sometimes restores it back to 36 volts for a short time. We are at a loss & don't know what to do next & would like some advice. Thanks in advance.