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Wayne Crawford
Wayne Crawford, Shop Owner
Category: Ford
Satisfied Customers: 4017
Experience:  General Repair Shop Owner
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Expedition: Fuel pump relay shorted out on my 2003 Expedition

Customer Question

Fuel pump relay shorted out on my 2003 Expedition 5.4 liter. Replaced the fuse box with a used one. The truck started but is not charging. Durnug troubleshoot, I noticed that a relay was missing from the fuse box. Put a relay in and the truck started charging at 13.5 volts. The next day while driving home from work the battery light came on. Had the alternator tested, replace all of the relays, checked the fuseable wire in the battery cable. Every thing checked out fine, but still not charging.
Submitted: 2 years ago.
Category: Ford
Expert:  Wayne Crawford replied 2 years ago.
Hello. My name is ***** ***** I will be helping you today.Lets just start from the beginning.Do you have a lab scope?
Customer: replied 2 years ago.


Expert:  Wayne Crawford replied 2 years ago.
Excellent! Check the tan/light green and brown/pink wires at the voltage regulator with it running looking for a good square wave signal. Let me know what you get.
Customer: replied 2 years ago.

I will have to get back with you later, not at the vehicle at this time.


Expert:  Wayne Crawford replied 2 years ago.
Alright. Just reply when you get those checked and let me know what you find. Thanks
Customer: replied 2 years ago.

Perform the test at hte voltage regulator and got a good wave pattern. I also replaced the alternator and still no change.

Expert:  Wayne Crawford replied 2 years ago.
OK. Everything checks out good. Your next step is to get the PCM reflashed. I am attaching a TSB about it.