U1900-6F, -E0, -60 after wire harness replacement. No Crank/ no Start.

[AZExploder]

2010 Mercury Mountaineer AWD 4.6l - 270,000 miles, all original.

Background:
For 2 years the AC clutch has cycled on/off rapidly when engaged. Runs poorly after warmed up until AC is disengaged.
For the last few months I have been chasing codes of every type - O2, Gas Cap, Tank Vent, Camshaft, Powertrain, Evap,
(P0345, P0349, P0054, P0060, P0455, P2197, P0341, P0346, P0101, P0220, P1516)+

Last week Installed new factory spec COPS, Injectors, plugs, Intake, complete AC.

No change. Ran great with no AC, poop when AC running. Wiggle test at wires coming out of the pcm indicated harness maybe an issue.

Installed new wire harness.

Now U1900-6F/E0/60. and no crank/start. I can hear the electronics start to wiz inside the engine when I turn the key, but starter does not engage.
Connected the neg post to the block with no change.
Compared wire harness with old plugs to ends.
Swapped in old COPS.
Wiggled all the wires.

Stealership will not have a look - even pull codes - since I did the work myself except for the AC.

Ideas on what to do before I put the old harness back on?

 

[Gmctyphoon]

You might just have a blown fuse right now.

What did wiggling the pcm connectors do before you changed the harness?

Where did the new harness come from?

 

[AZExploder]

View attachment 319148


You might just have a blown fuse right now.

What did wiggling the pcm connectors do before you changed the harness?

Where did the new harness come from?

I pulled all the fuses in the cab and under the hood. There was one blown that was replaced. I also added a new relay and switched them around.

The harness is from Ford dealer in MN. They verified it is correct for the vin - along with the sub-assembly.

Wiggle test was before replacing the harness - which was the last thing I did. My mec said the sensors would error, then be fine - back and forth - as he wiggled them. I also put the cops back in.

 

[Gmctyphoon]

So by wiggle test you mean when you moved the plugs directly on the pcm you would get problems?

If yes than what problems occurred?

And wiggling plugs on the ecu that cause problems almost always means a bad ecu, not harness.

 

[AZExploder]

So by wiggle test you mean when you moved the plugs directly on the pcm you would get problems?

If yes than what problems occurred?

And wiggling plugs on the ecu that cause problems almost always means a bad ecu, not harness.

it was the wires that were wiggled - not the plugs or the pcm - that caused the engine to pump out codes. I clarified that in my original post.

I pulled the PCM and it seemed sound. No pin discoloration and seals were fine. All the pins were straight . My service writer sister suggested sticking it the fridge (110 days for the last few weeks).

Today I pulled all the fuses out between lighting storms and tested the power to each. Came out clean. Tomorrow, the old harness goes back on. I think I will skip those o2 sensors tho - at first - and see if she will turn over.

Thanks for your input!

 

[AZExploder]

SOLVED
User error. Who knew.

The transmission plug has a lever that plunges the plug into the case when turned. The lever on the new harness was not assembled properly so when I pulled the lever down - the plug lever would engage, but not plunge the actual plug into the transmission to engage the pins. I contemplated this when I was removing the new harness and the lever fell on the ground.
I snapped the ring into the proper position - put it back on, and she fired up with the usual coughing and sputter of the untuned

now - 50 mile test drive to see what kind of codes await me.

 

[Gmctyphoon]

Awesome job finding that! And updating this thread.

Now you have to let us know if the harness fixed the truck.

 

[AZExploder]

Quest Continues. See Stuttering Clutch for updates.
No Codes so far - so that may be an entirely different rabbit.

 

[Gmctyphoon]

New Thread

A/C Clutch stuttering on/off.

2010 Mercury Mountaineer AWD 4.6l 3V - 260,000 Issue has been going on for about 3 summers now. AC is fine all fall, winter (defrost), and spring. Temps climb over 105 - 120 deg the symptoms come back. Recent Replacements chasing issue with the advice of ASE tech and all Ford/Motorcraft...

www.explorerforum.com