Looking for help please. Trying to determine why I burned out 3 solenoid switches. The golf cart is a 1993 Club Car DS with an electronic speed controller. The batteries are 5 years old but are fully charged and check out as good on my load tester. The cables are new and all connections are clean and tight. When the cart runs for just a few minutes, the large post on the solenoid begin to heat up. They will continue to heat up until they get so hot that you cannot touch them. On two occasions, the solenoid burnt out when going uphill (under a load). The solenoids where purchased from ebay and are not HD solenoids. They are sold as golf cart solenoids for 36 volt carts. The cart runs fine but fairly slow until the solenoid blows. Can the old batteries contribute to this problem? Controller maybe? Suggestions please. Thank you.