good to hear that helped, after looking in the troubleshooting part of the ev100 manual that was what it suggested for your symptom.
Just so you'll know, the #3 rec is the flyback diode, it's purpose is to generate a loop of the stored current in the circuit and motor and is called 'flyback current'.
The #4 rec is the plugging diode, this takes that flyback current and redirects it back into the battery when the direction is reversed during travel so while the motor is slowing down to reverse direction the flyback current is being directed back into the battery.

So if you cannot determine which one is leaking or shorted (i'm betting the flyback #3 is leaking), you should replace both if you cant determine which. The best way to check them is to use what they call a handyman tester which has a leak test mode on it. You can use a vom to test them but you'll need to put the scale on a high range so it can be sensitive enough to pick up the leak through. Remember it is basically a diode so it has continuity in one direction at around 7 to 12ohms and when you reverse the leads that is the leak test part and it should not have ANY continuity at all, if it reads anything it is leaking.
EV100LX manual describes testing the 3 and 4 rec's as follows:

"3REC and 4REC are diode with about 7 to 12 ohms in the conducting direction (anode to cathode) measure on the R x 100 scale, and 10,000 ohms or higher, in the non-conductiing direction (cathode to anode) measured on the R x 10,000 scale."