[e3sean]

ok i am yet to get my car started cause a few issues here is one..car ran when i pulled it into the garage changed the motor converted it to mass air so i swapped the wire harness.. i can not get it to turn on. looks like someone pypassed the inerta swith the plug is gone and it has a connector between the two wire.

where does the fuel pump get its power from?\
what are my options to fix it?


not sure if its any relation but i also can not get my lights to turn on...

[SALIV8]

have you plled up a schematic and checked fuses/relays/switches/etc?

[e3sean]

i checked all the fuses i found the relay under the driver side seat there is a power going to it but it wont switch it over to turn the pump on...

[SALIV8]

did u chek neutral safety switch?is it an auto? or your clutch not completely pushed?

[Onemanzu]

you know that the relay is good? i had a problem with an old Volkswagen relay... went through 3 before one worked

[e3sean]

it all worked before i pulled the engine out.. it has to have something to do with the new wireharness/computer or my error somewhere..

what i need to know is where the fuel pump gets its power source from like the ignition or a fuze box.

also when the car is running is the fuel pump always on?? if it is i can just wire it to an accessory 12v power supply

[ryans88gt]

http://www.veryuseful.com/mustang/te...nks-ign-ac.gif

This should help you. I would start by checking to see if you are getting 12v at the fuel pump when you cycle the key (maybe your fuel pump died while sitting).

If no 12V, check at the relay hot side (orange/blue wire). If no, blown fusible link. If yes, check the red/black wire should become hot when you cycle the key on and off (prime the pump). If no, your problem is in that circuit. If yes, most likely it is the relay ground, which is provided by the computer (tan green wire on the relay). try grounding this wire and cycling the key if everything else checks out. Hope that helps.

[crowbar73]

Dang Ryan, you beat me to it. I just went to my garage to get a wiring diagram. (I couldn't remember the wire colors). Oh well, I tried. P.S. your car is a rocket man!

[87 5.0]

Originally Posted by crowbar73 Dang Ryan, you beat me to it. I just went to my garage to get a wiring diagram. (I couldn't remember the wire colors). Oh well, I tried. P.S. your car is a rocket man!

Since when did mustangs become ROCKETS????

[e3sean]

Originally Posted by ryans88gt http://www.veryuseful.com/mustang/te...nks-ign-ac.gif This should help you. I would start by checking to see if you are getting 12v at the fuel pump when you cycle the key (maybe your fuel pump died while sitting). If no 12V, check at the relay hot side (orange/blue wire). If no, blown fusible link. If yes, check the red/black wire should become hot when you cycle the key on and off (prime the pump). If no, your problem is in that circuit. If yes, most likely it is the relay ground, which is provided by the computer (tan green wire on the relay). try grounding this wire and cycling the key if everything else checks out. Hope that helps.

i am getting power to the relay and it is not going to the red wire when the car is cycled so the green wire when grounded should put power to the pump? if that works its the computer..

[crowbar73]

if you don't get power at the red/black wire at the fuel pump relay when you cycle the key, i would go check at the inertia switch (in the trunk) and see if you have power there when you cycle the key. maybe there is a loose connection there. if no power on either wire there, you need to find the eec power relay and check for power there on black/orange wire. if no power on black/orange check fuse link G? If you do have power on blk/org it is probably an ignition switch failure. hope that makes sense?

[Black Five 0h]

any luck on this?

[ryans88gt]

He wasn't getting power at the red/black wire because his ECU relay was blown. Sean, hope you don't mind if I answer for you

[e3sean]

nope i forgot about this post.. yeah like ryan said it was the ecu relay was bad i replaced it and it all started working again.

just cause something worked when u used it last doesnt mean its gonna work next time u go to use it...i learned that the hard way...