2004 Ford Explorer PROBLEM!!!! HELPPPPPP?

Try to figure out where the clicking sound is coming from. Have somebody turn the key while you are under the hood. The starter solenoid is the small drum mounted on the side of the big starter motor (see the link for a photo). It that starter solenoid is clicking but not activating the starter then the wiring to the starter could be loose or corroded, the starter could not be grounded properly, etc. Take the starter off and bench test it. If some other relay is clicking under the hood then use a test light to check to make sure the starter solenoid gets power every time that relay clicks.

FO r some reason you don't have enough power in your battery to start the engine. Jump start it, and have your charging system checked at the local AUTO ZONE!!! It is a FREE check. POwer wash your engine. It is VERY common for road grime to coolect on engine connectors and cuase a current change over time. A clean engine ALWAYS works it's best. GOOD LUCK!!

if the battery connection is fine then 100% your problem is a bad starter solenoid. (where the battery connects to the starter, the key tells it so send electricity to the starter to crank over the engine)

See this every day on Ford products. Dirty battery cables. Probably the negative. That's usually the culprit.