Waiting on 04-08 5.4, 4.6 forum to respond so figured I'd ask the wonderful bull nose crowd. Good battery, alternator, checked many visual grounds and wires.
When you turn key you only get 3 single symptoms of all the normal functioning sounds, lights, power and function
1. Dash only flash air bag light
2. Speedometer jump from 10-25 mph
3. Buzz/Hum noise from somewhere above fuel tank.

Something I've noticed quite odd is truck will not shift from park with key in any position.
The chrome tab on front of gear shift rod will not depress as normal.
Even attempting to shift truck with the transmission gear selection switch (under truck on driver side transmission connects to shift lever) REMOVED and wont shift as well when depressing brake and rocking truck?


wth!? Anyone here have ways to test certain parts i.e. command start module or other possible culprits without having to throw $$ at the 08 guessing? I've got 2 1986 F350 4DR DRW to throw money at haha

 

Moved to correct forum.

 

I am surprised 3 days with no answers

 

I may have answered this somewhere . There is a shift interlock solenoid . It won't operate with low battery. Jumping instrument will happen with low battery .Bad grounds in kick panels . You can try jumping negative battery to different points . there is a wire disconnect going to your starter solenoid up top , mechanics open this and jumper positive to it to get crank without starting with key off . Makes it easy to test start command plus battery power test/starter test -- make sure its in park .
Its discussed in this post #315 https://www.ford-trucks.com/forums/1...linder-21.html'. You can use headlights also for load tests .