Fuel Pump electrical Issues

[Cali510]

Hello new here, Wondering if anyone can help me out. recently had my fuel pump relay burn up, pulled board and replaced relay, still wont start. Fuel pump works fine as bypassing the the relay running hot to the g/y wire starts the truck right up. Rather not continue driving without having the relay as i dont want to have to replace the pump. Is there something else between the relay and the ignition i should be looking for to be faulty? Know its not the inertia/ cutoff swithch as im bypassing relay before switch. 2003 expedition. Eddie bauer edition. 5.4

 

[whtbronco]

Pretty common failure around here. Check the fuse and verify the relay in installed correctly. It can be installed backwards. Well it's unlikely, but possible the replacement relay is faulty. Could have burned through the run on the board as well. I'm not sure off hand what else to check.

Newer central junction box(fuse panel) replacements have a 20amp relay instead of the original 15amp relay.

 

[Cali510]

Unfortunatly i replaced it twice and still have same problem. Does this relay run directly to ignition or through pcm? Does anyone know, i dont have a diagram for it.

 

[Yupster Dog]

Unfortunatly i replaced it twice and still have same problem. Does this relay run directly to ignition or through pcm? Does anyone know, i dont have a diagram for it.

This thread might help you
https://www.expeditionforum.com/threads/another-fuse-box-replacement.46781/

Welcome to the forum

 

[Cali510]

Thank you yupster, just the thread i needed. Going to try the external relay hookup this weekend. Now just need to find somewhere to put it, as my dog likes to ride on the floorboard even though shes 60 pounds and barely fits

 

[Vincent Vega]

Is the relay failing each time you replace it? If so, it may be that the pump still works but is drawing excessive amperage because it is in the process of failing. Thats what happened with mine and Usually that is the case in 03-04s, although it theoretically could also be short between the relay and the pump. Good luck and please let us know what you find out, or how you end up solving it.

 

[whtbronco]

You can get the service manual for the diagrams from AllData or here is another option: https://charm.li/Ford/2003/