UP DATE.....SOLVED !
Well as it turns out the Y connector that attaches to the post of the starter solenoid on the firewall is made in two configurations. with one the straight leg of the harness is for the starter , on the other the straight leg of the harness is the battery. I did not take the solenoid off so when I put it back on I simply looked at a photograph on a website. Up on rechecking everything several times I know this a different photograph and had it wired differently. so I tested the wiring to see which of my legs went to the battery and what do you know that's the problem!

Firstly thanks for the ad,
I have a 94 e150 it was running fine recently replaced firewall solenoid, then after a short time there was a burning smell and it had melted the solenoid on the starter, then everything went dead. I'm going to list everything that I've checked and that is working so please look at the list carefully rather than constantly make suggestions about things I've already tried, thanks.
Battery and battery connections are good, neutral starting switch is good, ground to body is good ground to engine is good, fusible link is good, all fuses under the hood are good all fuses under the dash are good . replaced starter solenoid replace firewall solenoid replaced actuating wire to the starter , the main power cable to the starter is good. I've cut into the wiring harness running under the engine to the starter looking for a short didn't see any obvious signs of it the trip wire going to the solenoid was bad hence the replacement.
So am I looking at a PCM problem? Again I have no power anywhere just prior to shutting off the headlights would not work if the engine was not running I only had exterior lights with the engine running ,then everything shut down.

 

You might have an incapable battery after whatever short or overcurrent melted the solenoid. It might register 12V with a tester yet have no capacity to drive a even a small load like brake lights or horn.

Sixto
07 E350 5.4 178K miles

 

No, if a battery shows 12.6 volts it will run something, I need it before that problem occurred it was starting fine and holding voltage properly. I'm not even getting a voltage reading through my meter, again, according to my list it is not the battery!

 

Do you have 12V at fuse S in the engine bay fuse box? Fuse S is powered by the battery then splits to fuse R, headlight switch and cabin fuse box.

Does the van have a factory security system that’s in lockdown? You should still have headlight and horn function though.

Sixto
07 E350 5.4 178K miles

 

I believe 94 150 would have an inertia switch. Has it been checked?

 

NEW DEVELOPMENT.....

Working from the PCM power relay fuse "S" WITH MY METER I HAVE NO VOLTAGE CHECKING EITHER SIDE TO NEGATIVE. I DO SHOW FULL VOLTAGE RUNNING EITHER SIDE WHEN CONNECT TO POSITIVE . AND I DO GET CONNECTIVITY IF I GO FROM NEGATIVE TO EITHER POST ON THE "S" FUSE .DOES THAT SOUND LIKE THAT WIRE GOING FROM THE BATTERY TO THE FUSE BOX IS GROUNDED OUT SOMEWHERE IN THERE??

 

Wouldn’t the battery be dead by now if there were a continuous ground? Is it possible the positive and ground cables are reversed at the battery? Disconnect both battery cables then check that (hopefully) only one has continuity to ground.

Sixto
07 E350 5.4 178K miles

 

No the battery is connected properly ,and I have proper meter readings testing positive post grounded against the body. It seems to me that I should be able to get a power reading by grounding fuse terminal, but I only get a power reading if I connect to the positive post the battery

 

With the battery disconnected I'm getting connectivity between both sides of the s fuse circuit , and the body ground

 

Just out of curiosity, because you have connectivity to both sides of the S fuse socket, and you said you melted the solenoid, could it be possible that the surge went into the back of the fuse block and melted wires together back there? I had this similar problem with an old 74 Ford 500, melted the solenoid, melted part of the back of the fuse block and melted the ignition switch housing plug....Just a thought.

 

Finally somebody didn't tell me to change the battery!
After checking everything else I came to the same possible conclusion , I don't see how it could be anything else I shouldn't have connectivity to the ground on either one of those posts in that fuse. tomorrow I'll tear the fuse block out and look at it.

 

So as mentioned I've got that problem with the S fuse connectors both throwing connectivity to ground I want to take out the power relay box but it just seems to have some snap s on it or something no bolts anybody ever take one of these out of a van ?

 

I'm not 100% on this but supposedly on a 1994 E150 there are quick release tabs on the fuse block, but also there is a metal bracket behind the block that holds the wire harness in place that must be removed so the block can swing down without damaging the wires.

 

Yeah they look like great big metal clips but I can't get them to budge I'll check the other hold down assembly on the wires first, thanks