Mark, how many hours run time do you get to a pump? Is there a difference in fluid requirement (still Dextron comparable) I would be doing a mod to a 964
Can you expand on the wiring, positive and negative wires, but is there a trigger wire that activates when ignition is on and is there a wire for a speed pulse sensor?

 

The electric power steering pump gets +12v from terminal 61 which is the alternator excite wire. The pump only runs when the alternator is spinning.

 

Geoffrey is right about the control signal. There is another hot that has to go through a switch on the dash or the ignition switch to turn it on and off. There is a third wire (large gauge hot) that has a fuse link that goes to your battery. Lastly, there is a large gauge ground.

The control signal Geoffrey mentioned insures that your charging system is working in order to run the pump. I'm told that sprint teams sometimes run that wire directly to the battery so the pump doesn't stop even if they have an alternator failure. They must be able to finish a race on battery alone.

Porsche recommends Pentosin (Servoöl) CHF 11S as fluid in the system. I don't know how long they go before certain failure. We replaced them at 15 hours regardless of performance so I can't remeber ever having a failure but we were replacing everything on the cars all the time regardless. I think teams are running them for several seasons without an issue.

 

Geoffrey -
The electric power steering pump gets +12v from terminal 61 which is the alternator excite wire. Is this based on the 996 wiring or is this a terminal location also found on the 964. I looked but could not find in the wiring diagram - Of course I can read those very well-
From what Mark says there are 4 wires that lead from the PS Pump - a positive and negative ( heavy wires) for main power supply that should be controlled by a relay unless the ignition wire controls. Then 2 secondary wires one that goes to terminal 61 which controls the pump when the alternator is working and another wire that is ignition switch controlled - this I am guessing goes to a internal relay in the pump or controls an external relay that control the main power supply.
Thanks for all the help -

 

On your 964, you'll find terminal 61 on pin 27 (verify your wiring is the same) in your ABS harness at the ABS controller. I splice the power steering pump wiring here. As mentioned, you can use anything that provides +12v. Some pumps have 4 wires (Big +12 and Ground, Term 61, and another +12v ignition trigger), others I've used have only had 3 (missing the +12v ignition trigger).

 

Geoffrey -
Are you talking about this - see attached PDF - pin 27 on the ABS control - says Valve Relay

 

Anyone know the wiring for a 6Cup? Black and Blue w/white tracer. I believe the black is ignition power and the blue/wht is the alternator trigger, but not 100%. If so, any idea how to hook-up to the alternator or can I just power them both at the switch?
Thanks