help me wiring the fuel pump! need help asap!

5.0kid · Feb 10, 2012

only back in town tomorrow and need to get the car running! i don't know where to go now...

http://www.veryuseful.com/mustang/tech/engine/images/Mustang-94-95-CCRM-PCM-Transmission.gif

ok, so I found the green/yellow wire for the fuel pump. according to:

http://www.enginebasics.com/Advanced Engine Tuning/fuel pump relay.html

I should just be able to cut the dark green/yellow wire and split it for the 86/87 wires right? then 30 is battery, 85 is ground?

before cutting the wire i was able to get it to prime when the key turned to "on" position, but now it doesn't turn the pump on at all. anyone, better at wiring have any ideas? need to figure this out tomorrow morning!!!!

ttocs · Feb 10, 2012

What are you trying to accomplish? Not sure what adding a relay to the wire will do unless you are having some problems. Be sure that the power side of the grn/yel wires is what is going to 86 and the pump side is going to 87 or it will realy not work at all then.

5.0kid · Feb 10, 2012

i'm trying to wire the fuel pump to run because i switched to carb. i read that i needed to do this relay to replace the one in the ccrm? I'm thinking i just need to get a good 12v wire to the 86 and i should be good? instead of using the ecu wiring? keeping the dark green/yellow the 87 wire?

ttocs · Feb 10, 2012

think of the relay in two pieces, the coil(what activates and moves the switch) and the switch. The coils terminals are 85-86 and you need power on one and ground on the other to activate the switch, doesn't matter which way either. If you are doing this because the ccrm no longer sends power to the pump then using the grn/yell wire to activate the relays coil will not work either. As you said all you need is a TRUE ignition to go to 85-86 but make sure it is a TRUE ignition normally only found in the ignition column. If you are not familiar with a true ignition, it will show ground with the key off, power with the key on as well as when the starter is cranking. If you were to tap the ignition wire that feeds the radio for example it would not work because power is cut to the non-necessary accesories while cranking the motor to start it.

5.0kid · Feb 10, 2012

ok, cool. thanks a lot for all the info! haven't been on here lately, been annoyed at the stang and found out today that the reason i've had such trouble with it the last 1.5 years, was a problem with the grounding of the engine. Not sure how, but it wasn't getting grounded! hopefully should have my first start up video up tomorrow

Raffaelli · Feb 11, 2012

I would personally put the fuel pump relay in the passenger side kick panel. The green/white wire goes from the fuel pump, up the drivers side floor rail, crosses under the dash, thru the passenger side kick panel to the engine compartment to the CCRM.

Just suggesting there because its neat-ish and has all the wires youll need to put a relay in. (cept for a fused battery feed).

ttocs · Feb 11, 2012

one last suggestion. Putting a switch on one of the wires going to 85/86 will work as a perfect starter kill if you ever parked it somewhere that you wanted to ensure it would be there when you come back. Flip the switch and the car would crank till the batt died but will never start, good security if you hide the switch.