Re: pcm/efm fuse 98 5.4 expedition
That relay when triggered, runs power to the engine components, ie. injectors, MAF, O2 sensors, and more. There must be a wire shorted in the engine compartment. Look at the whole harness and see if it's against something and grounding the wire. I'm pretty sure it's red.
You didn't mention if it had alloy wheels? LOL Don't worry about the info. you mentioned. It's better than not enough.