
I don’t know what Ford used for wire casing in these vehicles, but it is more like plastic than rubber if you know what I mean. I actually own an 04’ Explorer XLT myself and I have found some rather disconcerting issues in the wiring department. Im sure you will figure this out quickly. Its nice not to have to do that this time honestly. Cant tell you how many times me and the other fine people here try to explain relays, their terminals and the circuits they exist in. You are waaaay ahead of the game with the tests and knowledge you already have about how it all works. Other than using a meter on the starter relay you removed… Not rocket science… I’m fairly certain you will have identical relays within your fuse box…there should actually be more than one that you can swap into the starter relays position as a quick test of this theory.

Often times you will have a clicking relay that has burned contact points internally so despite it seeming healthy…it actually cannot let current flow between 30 and 87.

Yes you are correct about the terminal description…and it is good you tested the system the way you did jumping the panel side 30 and 87 to see if the starter reacts is precisely what you needed to do to test the circuit.
