There is something wrong into the explanation.
A: start with the SRO test static to return off.
Means key on, start switch not activated.
EV100 start trough SCR 2 (loading the capacitor)
Check capacitor. Must be loaded before any function will start.
Select the direction switch (if there is no PMT fault) Pulse monitor fault) above system is oke.
Push slowly the acc pedal (starting the wheels turning)???
Check input potential meter input R4 on the card from +/- 4.5 until 0.5 before 1A will close.
If any question is left please comment this message.

If he had a SRO fault, it wouldnt pull in the contacts or hum
hence the "off" in "static return to off"
if the switches were bad it wouldnt do anything

hes saying the only way to get it to move is to push in (by hand im assuming) the 1A and one of the FWR or REV contacts
and that regardless of which directional contactor is pushed in it will only go in reverse

im also assuming it wont drive in either direction by operating normally (sitting in seat, using the pedal and dir lever)

so... from my assumptions and the very little amount of information the original poster provided
i would think that he has some cables shorting to the frame

it also could be a short in the motor
if there is a lot of battery acid built up in the motor or frame this can cause odd issues and shorts


but since we dont know what machine this is in
we have no way to know if you have 1 drive motor or dual drive motors (i assume a single) the position of the motor etc

please post the model and serial number
or
the model number printed on the EV100 card itself (there are many different setups for different makes and models)

without that info a lot of this is just guessing

forward reverse switch on the collum bad.do you have to SRO the machine to make it run.SRO means switches required on.Most people call it static return off.

I am hoping the "a3" you are referring to is what I call the 1a or bypass contactor.
when you have the "good hum with accel" are the wheels turning in the correct directions?
a make, model and serial number would be a good thing to always add to your posts when you start a new thread