hi,

im trying to find out which wire is + and neg on my fuel pump. i want to confirm if its working by running 12v to it directly.

95 LS400

 

based on the picture, the ground is the white wire as it mates to the housing.

also check this out as a further troubleshooting step:

 

thanks, i did all those tests weeks ago. i jumped the pins B+ and Fp. no luck, no noise from pump or fuel from return line. i just want to make sure its safe to run 12v directly to the pump on those wires- or else ill just take the pump out and tap into the terminals on the pump.

 

White is ground, remove the fuel pump connector from the car before you give the pump direct power you don't want to be pushing power back into the ECU. Likely not an issue but don't take a chance.