I have a 1988 RX-7 GX(essentially a base model with power steering and sub zero start assist)

Anyways I just got it back from the shop. They had my entire idle system apart because it was doing some funky stuff. Anyways the power steering seems to not be working. I read up some stuff in a haynes manual but they don't talk about how the power steering works only manual.

It's a S4 setup so I don't think there would be as many electronics in it as the S5. All I know is that it's triggered by speed. I don't think the rack is worn because my car only has 55,000 original miles on it. Fluids are at the full marker. It worked fine before I had it in the shop.