2007 Lincoln Mark LT 5.4 3v no crank, no start

2007 Lincoln Mark LT 5.4 3v 191k, no crank no start left me stranded at store, replaced 4 year old battery, still no crank. Figured it was starter, I put new starter, still no crank. No power/signal at starter solenoid on the starter when trying to start, I put test light on battery positive to pin 85 to check for PCM grounding relay, it lights up when you try to start. I replaced ignition switch, wasn't getting key in chime, now that works, but still no crank. I replaced Neutral Safety Switch, still no crank. I verified with Topdon Phoenix scan tool, NSS is accurate, wont start in neutral, recognizes all correct gears. Ignition switch recognized all positions, off, ACC, run, 12v gets sent down ignition wire when trying to start. I removed aftermarket remote start prior to all this. PATS system proves out, I even re-learned the keys. Continuity test from negative cable at battery post to starter ground, zero ohms. I replaced positive terminal at battery main connector just in case, still no crank. I switched out starter relay with known good and new, still no crank. With cover off relay, I can push plunger to engage pins 87/30 fires right up. Scanner shows starter solenoid commanded ON when trying to start. There is 12v constant at starter. I'm at my wits end here, what am I missing?

If the starter solenoid is commanded ON, it means that the Pcm receives the inputs needed for enabling starter engagement. You are most likely dealing with the output: the relay. I am pretty sure the pcm would not command the starter ON if the PATS system had a issue. You need to check for power at pin 86 and control at pin 85 as well as power on pin 30. (If the vehicle starts when you jumper pin 30 to 87, no need to check pin 30.You are must likely dealing with an open wire from the Neutral safety switch to the relay or an open control wire. 

So bad connection or socket at the relay, need to change the fuse/junction box, ugh what a PITA, you gotta be a contortionist to get up in there.

Think what would it take to start? We know if the relay is closed manually it starts. Give it what it wants to start. the relay needs 4 inputs and outputs to run. Load test the wires with your test light. Try grounding the relay directly on terminal 85. and providing power to 87 directly. If the switch side is operating manually, the coil side should be the problem.

Do you get 12 v at pin 86 in start position?

I grounded pin 85 and put 12 v test light from battery to pin 87, it illuminates.

I get 10v volts at pin 86 at start.

With the test light connected to battery positive, slightly touch pin 85 and have someone crank the vehicle. The test light should illuminate.

Yes it does

Connect the black lead of the voltmeter to batt positive and the red lead to pin 86. See how much voltage drop you have.

11.5v and battery at terminals is also 11.5v

With black lead to battery positive and red lead to pin 86 with key in start position you have 11v?

Im getting nothing, maybe fluctuating mvs with battery positive to black lead and red lead to pin 86 when trying to start.

.3 v or less is acceptable.
It is kind of weird. You have good feed to pin 86 and control to the relay from the pcm, good feed on pin 30. Does the relay even click with key in start?

No clicky clicky, I am being co cked blocked, beyond frustrating, maybe the PCM is grounding pin 85 but not enough to pull the switch.

All Okay Auto wrote:

Think what would it take to start? We know if the relay is closed manually it starts. Give it what it wants to start. the relay needs 4 inputs and outputs to run. Load test the wires with your test light. Try grounding the relay directly on terminal 85. and providing power to 87 directly. If the switch side is operating manually, the coil side should be the problem.
Try the suggestion from All Okay Auto. I missed his post.
 

I answered it: I grounded pin 85 and put 12 v test light from battery to pin 87, it illuminates.

If the test light were brightly illuminated, I would say that the driver is not weak. I don't want to tell you to ground the control wire and try to start it because I do not know how the pcm driver would be impacted.

The relay pins are not spread by any chance?

This darn fuse junction box is in the most awkward position passenger side floor board under A pillar. I got my eyes on the socket but it's really difficult to see to tell you the truth. It doesn't appear they're spread and even if they were, there's no way I can get in there with a screw driver or pick to tighten them up, I tried! I'm considering putting some solder to fatten up the pins on relay to see if does anything. I just broke the darn lock key cylinder after the key wouldn't release, I got new cylinder motorcraft coming tomorrow and new PCM and junction box coming by Saturday.

I grounded pin 85 and 12v to 87, nothing. I don't remember if I grounded 85 and 12v to 30 if that's what you're inferring. The only logical answer I see is that the leg between 85 and 30 is broken. I remember my Viper remote start had 3 inline fuses and one was blown, maybe that's a clue that it fried that circuit. I replaced the fuse before removing the remote start but still nothing. I paid the vehicle off from the get go and I haven't had a car payment in years so unleashing the parts cannon was not unreasonable for me. $160 for Plug and Play PCM from eBay and used fuse box under $100. The learning experience is more valuable to me and I am for sure a tinkerer enthusiast. Hope to post update soon, this day job gets in the way, lol.