ECU keep alive

[Bicyclops]

Info added for +12 Memory power for ECU
02-05 WRX ECU pin D10
06-07 WRX ECU pin B5
04-07 STI ECU pin B19
04-07 FXT ECU pin B19

Thanks, Bob.
So that's the black/red wire on B137 on the '02 WRX?

That seems to also pick up the fuel pump relay and the main relay among other things. I was figuring to wire those separately to fuses after the battery contactor. When I think about it, the main relay may be superfluous if the batt contactor is shutting off everything but the memory. Oh wait, there's the accessory position on the key switch. Don't know that I'm running much on that.

Speaking of fuel pumps, I am running two AEM pumps (one in a swirl pot). Do you think the stock fuel pump controller is good for both of them ampwise? I guess the alternative would be to use the fpc for the swirl pot and just let the lift pump run full tilt on a separate relay. It won't make any pressure to speak of, just overflow back to the tank.

Ed

[Bicyclops]

I'm hoping to not be letting the car sit long enough to run the battery down here in (currently) rainy SoCal. ;-) I'm thinking that trip ODO will be useful for figuring gas mileage and is my fuel gauge anything like accurate.

Ed

[Bob_n_Cincy]

Thanks, Bob.
So that's the black/red wire on B137 on the '02 WRX? That is correct

That seems to also pick up the fuel pump relay and the main relay among other things. I was figuring to wire those separately to fuses after the battery contactor. When I think about it, the main relay may be superfluous if the batt contactor is shutting off everything but the memory. Oh wait, there's the accessory position on the key switch. Don't know that I'm running much on that.

Speaking of fuel pumps, I am running two AEM pumps (one in a swirl pot). Do you think the stock fuel pump controller is good for both of them ampwise? I guess the alternative would be to use the fpc for the swirl pot and just let the lift pump run full tilt on a separate relay. It won't make any pressure to speak of, just overflow back to the tank. I do NOT think the fuel pump controller can handle 2 pumps. The fuel pump controller veries the speed of the pump depending on engine load. So the FPC should control the pump feeding the fuel rails. The pump feeding the swirl pot can run off the fuel pump RELay.

Ed

Bob

[Bicyclops]

Bob

That is what I was thinking, Bob. As I understand it, the fpc slows the pump down when the car is idling or at low power so as to not needlessly heat the fuel up by over pumping when there would be no problem maintaining rail pressure.

It looks as if the instrument cluster hot wire is A10, a blue/red wire in the green connector I10. On page METER-04 it is labeled POWER CIRCUIT and traces back to what looks like a straight battery + connection through a fuse of unknown amperage.

Ed

[Dave 53]

Thanks, Bob.
So that's the black/red wire on B137 on the '02 WRX?

That seems to also pick up the fuel pump relay and the main relay among other things. I was figuring to wire those separately to fuses after the battery contactor. When I think about it, the main relay may be superfluous if the batt contactor is shutting off everything but the memory. Oh wait, there's the accessory position on the key switch. Don't know that I'm running much on that.

Speaking of fuel pumps, I am running two AEM pumps (one in a swirl pot). Do you think the stock fuel pump controller is good for both of them ampwise? I guess the alternative would be to use the fpc for the swirl pot and just let the lift pump run full tilt on a separate relay. It won't make any pressure to speak of, just overflow back to the tank.

Check out the 2-13-22 "Surge Pump Return Hose" thread in the fuel system forum that discusses wiring 2 fuel pumps.

[Bicyclops]

Check out the 2-13-22 "Surge Pump Return Hose" thread in the fuel system forum that discusses wiring 2 fuel pumps.

Thanks, Dave.

My harness is chopped into pieces so I don't really have to worry about locating where splices are for the most part, just have to wire every little thing up and hope I don't miss anything. The aftermarket fuel controller looks like it could handle both pumps what with a 30A fuse and all. I think I'll wire the OEM controller to the surge tank pump and let the tank pump run full tilt for now and see if it causes problems.

Ed