Gonna highjack this thread since I'm currently having some issues with power steering right now and need to rule a few things out. First - I bought the car as a project and had to buy all the power steering parts for it (pump, lines, radiator fan, rack...) so everything here can be assumed 'questionable'. At the same time the motor was rebuilt and has about 20 minutes of run time on it so reducing idle time or engine stress is a priority for a little while. With the car in the air I can grab the wheels and turn them side to side like there's hardly any resistance, and when the car is running it doesn't seem like there's any power assist.
Leaking can be ruled out - the lines have no oil on them
Fluid can be ruled out - it's brand new ATF +4
Radiator - jury's out, haven't seen the hydraulic fan physically run, but the engine is new. Sounds like you can pull the coolant temperature sensor to test the fan's hydraulic circuit? I think I also read that relief pressure could be tested?
Pump - Will have a power steering pressure tester available to ensure pump is in spec
Rack - rack is dry
ECU - no guarantees, EMIC throws code 13 "internal bus failure" and I have no reading for oil temp, oil pressure, or fuel. Coolant temperature and voltage read fine
Lastly the fluid doesn't have any air bubbles in it and has never been warm to the touch after driving it around the block which also seems to point to the hydraulic relief valve.
Between being able to grab the wheels and move them lock to lock, literally 0 power assist, no air bubbles, and the fluid isn't even warm to the touch, I'm suspecting the the relief valve but if anyone has anything else they can think of to check I'm all ears here.