HELP , MY 91 F-150 4.9L WONT START...
I'VE REPLACED THE ; STARTER,SELINOID,COIL,DIST, PLUGS,WIRES,STARTER SWITCH,FUEL PUMP RELAY,EEC RELAY,FUEL PUMP, BATTERY,OIL PUMP, AND STILL WON'T START IT TURNS OVER REAL SLOW AS IF IT IS TRYING TO START DRY AT THE END OF MY ROPE. NEED HELP

 

Have you checked all your ground cables?

-starter itself
-battery cables

Are the wires connected good on the starter?

Thats all I can suggest. Somebody else here will have more and/or better ideas

 

No that is pretty much all there is too it. Make sure both ends of your battery cables are making good conntact and the cables themselves look good.

 

ANY SUGGESTIONS

 

Put a voltmeter from the starter wire (AT the starter) to the block and see what it is WHILE it's cranking. Repeat across the battery. Post those 2 readings and the reading across the battery at rest.

 

are you sure the motor is seized?

that doesn't happen very often. (With a 6 cylinder)

You can spin the motor with a socket and a ratchet on the crank pully. If it is an older motor you can turn it very slowly by hand, a little.
If it is a manual you can always pull start it.