i wouldnt go pressure washing any modern forklifts
including IC trucks
ive had problems where the customer pressure washed the engine and moisture was blasted past the weather proof connections for the ECM and injectors and caused all kinds of problems

in fact i discourage washing anything with electrical in it (including old IC trucks) a lil moisture and corrosion can go a long way to cause big harness headaches

i had a customer who washed his linde e16-02 (324) and it came up with a code 42 which is a bad power unit or moisture in the drive motors

the customer thought i was nuts when i told him to let it sit for a week to dry completely (after testing the power unit and associated wiring and it all came back good)
10 days later it was up and running and went months b4 it had even a minor breakdown (he got really lucky in other words but then again that was a low pressure wash)

electrics out in the rain drives me nuts too
a good analogy to make is to tell the customer who insists on driving an indoor machine outdoors in bad weather "take your brand new flatscreen HDTV and watch it out in the rain, how long do you think itll last?" most get it after that