Power steering pressure sensor location

We cannot find where the power steering pressure sensor is located. There must be one, right? Unless there is something else, some other mechanism, that is responsible for kicking the RPM's up when you are turning the wheel at idle. The power steering pressure sensor is mentioned in the Chilton repair handbook we have, but there are no images, or diagrams of it, and it says it should be located on the steering gear but there is nothing on the steering gear. This book covers multiple years and is not specific to the 2003 Astro, though. We have worked on this vehicle for fifteen years and basically know every inch of it, but this has us stumped. Have taken everything apart, followed the power steering lines from the pump to the steering gear and brake power booster and back to the reservoir and cannot find anything that looks like a sensor. Do you know where we can find it? We are 95% certain that is what the problem is based on researching the symptoms, and it seems like it should be replaced if we can find it. Of course, it is possible we are barking up the wrong tree.