94 Hino GH super eagle, no headlights, no wipers, no exhaust break, no break lights

Sometimes the wiper linkage seizes and sometimes a worn link will become detached, leaving the motor running but the wipers unmoving.

It is very rare a wiper motor breaks but the switching for the self parking wears out.
Other than checking multiway connectors haven't worked loose there is little you can do without checking the supply, ground and switch and that is made much easier when there is a wiring diagram.

Look around headlights for small bolts like a star one side is up and down, the other is left and right.

I would look for a blown fuse somewhere.

the low speed piston is not moving
could be dry and need lubrication
possible probble in the button , not allowing air pressure past when you select the low range
check for blown plastic line from button to box

All Hino manuals are here:
http://hino-rb145.com/manuals.php

Headlights are covered on page 55 of this manual
http://hino-rb145.com/manuals/Hino%20RB%20145%20Owners%20manual.pdf

change the wiper relay.

Could be a a clogged injector or fuel filter. Fuel filters are cheap to replace, a quality injector cleaning is around $120. Do you have check engine light on, if so I bet there would be a faulty o2 sensor, this causes the exhaust system to read excess fuel in exhaust and refuse to allow more gas through.

heres a wiper linkage asm diagram, the wiper washers are on the hood or on the cover to deck,then the hose runs through the wiper arm to a nozzle, if you remove the arms you can lift cover enough to look at the hose to washer connection,also check hose to arm they often break there good luck.

You have to have the headlights on for the headlights wipers to work.They don't work with the headlights off.