Buzzing in fuse box

[Dan1]

I replaced the fuel filter in my 2003 expedition. When I was done I started it up and it ran perfect for about a min. It shut off on me and started buzzing from my fuse box. I've replaced all my relays and even took my fuse box apart to check the relays on the circuit board. Everything looks fine. Anyone with any suggestion?

 

[stamp11127]

Which relay is making the buzzing sound? What is your current battery voltage?

 

[Hamfisted]

The circuit board fuel pump micro relay may "look" fine, if it hasn't gone extreme hot, to the melting stage yet. Turn the key on and put your finger on the relay that's buzzing. If it's the micro relay right in the center of the fusebox in that gap, it's the fuel pump relay going bad.



-Mike

 

[Ed_Strong]

The circuit board fuel pump micro relay may "look" fine, if it hasn't gone extreme hot, to the melting stage yet. Turn the key on and put your finger on the relay that's buzzing. If it's the micro relay right in the center of the fusebox in that gap, it's the fuel pump relay going bad.



-Mike

I agree 100%... my fuel pump relay did not melt, smelled burnt or had any indications that it was failling... all I had was some slight discoloration of the PCB between the relay and the points it connected to!
After I replaced the relay, all problems were gone!