I believe you said in another post the cart was a 2005 non PDS cart. If so you should have a resistor on the large posts and a diode on the small posts. resistor value is 250 Ohm 10W, diode value is 1N5408 3A. The stripe on the diode must aim at the terminal the small red wire is connected to on the solenoid. The resistor isn't polarity sensitive and can be installed in either direction.
On a PDS cart I believe there is only a resistor. 250 Ohm 10W. (same value as a non PDS)
You should be able to get them at a decent electronics store. If you can't find the locally JackRabbit or CartPartsPlus should carry them both.
The EZGO part numbers are:
Resistor - 21764-G1
Diode - 30351-G1
The above resistor and diode info is for stock application on a 36 volt cart