The WT is nothing like the WP at all WP uses Curtis controller WP uses zapi. has it got electronic steering???? It does make a big difference to the codes. Fixed or folding platform????. The code I would look at first is the 304, check and clean the estop does the dash turn off when you isolate the truck as it has a micro switch on the bottom the fails all the time. Strip and clean the main switch they are prone to dirty contacts due to dust ingress finally is the battery good???? 304 is a power issue and a truck showing 304 will throw other codes as well.