1. FocusEV Home 2. About Me 3. Decisions, Decisions 4. Acquiring the Parts 5. Removing the Engine 6. Mating the Motor
7. Battery Placement 8. Beefy Suspension 9. Wiring 10. Fuel Gauge 11. On the Road 12. Pictures of the Project
13. Tach and Speedo Fuel Gauge Power Steering Pump      

FocusEV Power Steering Pump Installation

I purchased a used 2002 Toyota MR2 electric power steering pump from a junkyard that I found through the website www.car-part.com

It looks a lot like this one.

Toyota MR2 Power Steering Pump

I installed it under the front drivers-side fender after removing the bumper from the front of the car. I mounted it using the three rubber bushings that came on the pump, to isolate noise and vibrations from the car. I took the fitting that came out of the steerign rack, along with the pump, to a local place that does work on hydraulic lines. (Pirtek in St. Paul, MN) They made up a new high-pressure hose to the length that I needed.

I purchased a 70 A automotive relay (Digikey part number 225-2079-ND - around $6) and mounted this under the hood. I studied the wiring diagram for the pump in the original car, and found websites from other people who had used this pump.

Important Notes:

1) The connectors in the upper right of the wiring diagram show the plugs that would be part of the wiring harness, not on the recepticles on the power steering pump itself. Since you probably don't have the Toyata wiring harness, refer to the picture of the recepticles on the pump, shown below the wiring diagram.

2) Connector P6 is the connector on the Power Steering ECU labeled with a circled "A" in the wiring diagram.

3) Connector P7 is the connector with the circled "B" in the wiring diagram.

4) Connector P8 is the connector with the circled "C" in the wiring diagram.

Original Wiring

The connections that I made to the pump are shown in the picture below. However I discovered that connecting the vehicle speed sensor to the to the pin shown had no effect, so I disconnected this. Instead, I connected the relay to apply 12 V to the pump whenever the key was turned on. This means that the pump was always running. Since that original installation I've added a small Arduino microcontroller that uses inputs from the vehicle speed and the brakes to automatically turn the pump relay on and off dependent on vehicle speed and how long the vehicle has sat sationary. Someday I'll document that project separately:-)

PS Pump Connectors

Updated 17SEP2010