I have a 2004 F-150 4.6 2WD with 103k miles. I haven't had any problems with it, till now. A few days ago I parked it in a parking lot, and when I came out to leave, it wouldn't start. The dash lights up, the fuel pump comes on, but the starter doesn't do anything. I thought at first it was the battery, so I went and replaced it. Nothing, so I crawled underneath and turned the nuts back and forth on the solenoid, thinking they had corrosion and weren't getting contact. Nothing, so I went back under and jumped the solenoid with a screw driver, which made it spin, but the starter wouldn't engage. I gave and had it towed home. I took the starter off and had it tested at Oreillys who said it was shot. I then went to a salvage yard and got one from an 06 F150 with 36k miles. I put it on all shiny and new looking, only to here nothing when I turned the key on. I went under with a multimeter and the hot wire to the solenoid read 11.8Vs. I had some one turn the key on and hold it in the start position, but there was zero voltage in the other two wires. I then switched out the starting relay, which also did nothing.

I am running out of ideas? Any thoughts?

 

2004 F150 is equiped with PATS(passive antitheft system),if it doesn't receive a proper transponder code from the key it won't even crank!1st thing to check is turn key to run position and watch what the red theft light does on the dash!if it goes solid for 2secs and goes out it's not a theft system problem, if light blinks fast and continuosly you have a PATS problem,maybe deprogrammed key or transceiver problem!