02 windstar No Crank! HELP!

[CAMSINTHEBORO]

Ok! I'm Reaching here. There are so many problems with these things. 02 Windstar was towed into my shop with a no crank issue. Scanner will not connect with computer. Listed below is everything I have checked/tested to date.
*Battery is good
*Starter is good
*fuses/relays good
*Ignition switch
*PCM
*Front electronics module(since ignition switch to starter runs through it)
*checked continuity from PCM to data link
*neutral safety switch
*diode

Here is the strange part. Dash lights up (theft light not blinking/ or on) turn the key to start position and dash lights go out like it's not in P/N. I connect the battery charger and crank it up to 200amps it will crank. I have looked through the numerous pages of posts. I hope someone has some insight.

[12Ounce]

You would do better with a wiring diagram... then you will see there can be one or more relays in the path of whatever one is trying to turn on ... extra voltage will help the relay-contacts to "make", completing the circuit. I would replace with new: the "PCM power" relay, and the "fuel pump" relay. EDIT: .... I forgot the most likely relay to be the trouble: the "starter-interrupt" relay.

Also I would revisit fuse #17 inside the cabin.

[kevink1955]

That's a classic symtom of high restance at the battery terminals, when you put the 200 amp charger on it is supplying the current to allow it to crank. I bet without the charger on it not only do the dash lights go out but all the lights go out also.

The only other thing it could be is a battery with high restance beteween cells, I know you said it had been tested but was it with a volt meter or a load tester?