This is the start of the issue I had:
https://www.ford-trucks.com/forums/1604880-94-f150-at-5-0l-transmission-oddity-need-help-please-2.html

To Keep it short, I replaced the shift solenoid pack. At this point I simply dropped the trans pan, pulled the filter and swapped the shift solenoid pack. The TC had not been drained yet because I wanted to see if the new pack would resolve the issue. Before I did anything else I fired up the truck and ran the selector through all gears. It was literally like brand new. Smooth as butter shifting and engagement of R,D,1,2 back and forth. No power dips and no stalls. Quickly shut it off.

put new filter on trans (old seal was out yes) new pan seal and pan back on. Then dropped the trans and did the rear main and oil pan seal drive shaft u joints new exhaust seals etc and a bunch of other non related work.

filled the trans up with 5 quarts to start. Turned on the engine and it fired up perfect. Idled it in parkm Let the pump suck fluid into the tc. Then slowly filled trans up through dipstick. Did not even drop truck off the jack stands. Put the selector in D and it stalled again
Now right back to square one. Exact same symptoms as previous post. Only code present now is the 629: "Torque convertor clutch circuit fault - transmission"

Good news is nothing leaks and the work had to be done anyways. But I'm back to square one with the issue.

I'm at a complete loss here guys. What the f**k is going on. I dont have even a slight idea where to start on this. How is it possible it worked when the new pack was installed before putting the filter back in and closing the pan!?

 

been easier to just posted resluts on one thread, so everyone see what you have done, instead of sending you down same bunny hole, but anyway please...
go back to your thread on this, and read and do what Mark says, again on post #5 and #7 ( i havent figured out how to get quote from one thread and post in another) some kind of magic ju-ju I guess! lol, did you disconnect battery for 10-15 minutes to make sure codes cleared, then warm to operating temp, then check for codes
94 F150 AT 5.0L Transmission Oddity. Need Help Please! - Ford Truck Enthusiasts Forums

 

I apologize I'm junk with computers.
I think I may have found the problem. Theres a spot in the harness cable bunch that has a good crush spot from previous work by old owner.....
I'm going to open it up and see if I have a crushed wire. Or a short in the bundle.
I'm under the truck right now with all harnesses undone again and following the whole thing.
it's possible when I checked the pins with multi meter the wires were not crossed likewise after manipulating the harness to remove the old pack....
I'm starting to feel like Clark Griswold trying to get his f**king Christmas lights to come on here...
I'll post back after I cut into the sheathing and check the crushed spot.

 

Yeah if the converter lockup line is shorting to ground,it's locking your converter and stalling the engine at idle.You probably found the issue.

Quote the person's quote you want as if you were going to quote it there in the same thread.Then either do one of these:
Drag and highlight the whole quote using your mouse by "left" clicking (hold down) and scroll over the words OR use keyboard shortcut; CTRL (button) and A (button) it will automatically highlight it.
Next "right" click the mouse button on the now blue highlighted quote and select "copy" then "right" click the mouse button again in the body of the new post place that you want and select "paste". The magic ju-ju is complete and you just hit post as always.

 

Please tell me I'm reading the bold part wrong. I see that as you fired it up and ran the selector through R, D, 1, 2 back and forth WITHOUT THE PAN ON! Is that what you did?

If so, the reason it was so smooth is that the trans can't do ANYTHING with the pan off. There is no fluid to create pressure to apply any clutch. So no matter where you put the shifter the trans will always be in neutral. Oh, yeah, without the pan on the pump has no fluid, which means it isn't getting lubed. You are very lucky that you didn't destroy the pump. In fact, I'm surprised you didn't destroy it.

That says that the problem is electrical. Only an electrical short or open can set that code.

 

Mark
If I was a liar I would make something up to save face :S
I'm learning as I go with this. Like I said I'm ignorant of transmissions complete. I took this on to learn and pass time as a project.

I had it running for maybe 10 seconds. Ran it through the gears once and shut it off. Consider me lucky. Pump showed no damage when I dropped the trans etc and inspected everything. Engine runs fine now with it filled up and was engaging in R and 1 just as before.

That does make sense though. I split the sheathing and found crushed wires in the harness bundle. Including what looks like wires to the shift solenoid. It looks like the last owner crushed the harness at some point. It was not easy to spot.

I'll be splicing the wires and sealing the harness back up. After all this it was electrical.
On the plus side, I tackled the job. Learned a hell of a lot. Now have a sealed crank, oil pan, trans pan, t case, u joints and a properly sealed removed smog system.
I have zero doubts this will fix it. Thanks again for the patience and education.

 

That's how you learn! Certainly not by paying someone to do it. Good to hear you got it.

 

The pump wouldn't have shown any external damage.You would have had to pull the trans out,removed it and then split the pump in half to inspect the surface where the gears spin inside of it,to know if you started to burn it up.You'll never know now how much damage you caused.You'll probably be ok but 10 seconds running dry even at idle didn't do it any favors.

 

Okay. So back to square 1 again here.
New solenoid shift pack installed in trans. Trans is sealed up again and mounted from all the other major work.
I pulled the entire harnes out of the truck. From the pcm connector on the driver fender back to the trans and neutral safety switch.
probed each harness to harness based on circuit diagram to ensure I didnt cross any wires. Continuity confirmed all wires connected properly by pin location end to end with multimeter.

using multimeter I have checked every single circuit from end to end and there is continuity on all of them. Equal amount. I cut off the old harness at the trans and wired in a new aftermarket repair one I had ordered anyway as the wires were looking a little rough. What I thought was insulation was dirt after cleaning up and some of the wires were exposed and potentially had crossed eachother. Wired new harness in, Checked for continuity checked for short to ground. Even checked the neutral safety switch circuits. All good.
Then i unbolted the pcm and checked cont/short to ground on the circuit for tcc solenoid (purple yellow prominent wire) to the harness on the fender. Good to go.
then I plugged the harness into the connector on the fender and again tested the solenoid pack harness tcc circuit all the way to the pcm corresponding pin. Gtg cont/no short.
Turn aux power on with the solenoid harness not plugged in and check for voltage and its getting power. Voltage to the solenoid harness confirmed.

clean all contacts with cleaner and put some dielectric grease on all terminals. Plug it back in and fire it up. Truck runs amazing. Put it in R good to go. Over to 1, dip in power and engine stumbles but it catches up and then works fine in 1st gear. I can drive it all over in R and 1. Put it in D and bang dead again. Throwing another 629........only 629....

how is this possible?!?!

Im at wits end here. Is it possible that the frayed wires made contact before I took everything apart when I first had the problem, maybe power line contacted/crossed the tcc solenoid line and send power to the pcm and fried the resistor in the PCM?

Any advice or tips here would be greatly appreciated. I'm losing my mind lol

 

Low trans fluid could do that.

 

Another interesting side note, I unplugged the shift solenoid harness only and fired up the truck. It stays running in D with the harness unplugged.....actually it runs 100% fine in all trans selections. With the harness not plugged in. I drove it forward 10 ft in D. Put it in R and backed it up drove it 10ft forward in 2 and then backed it up.

What in sam hell is going on here? Lol

 

Trans fluid is reading good on the dip stick while running in park.
Can anyone make sense of where my issue is if I have the harness unplugged and the damned truck is now able to select all gears on the dash with no power issues and actually drive normally in a short distance?

 

Mark,

trans fluid seems to be good.
it's still throwing the 629...

With the harnes not plugged into the solenoid insert, its will shift between all selectors in dash with no power dips at all and I can move it forward in both D and 2.

I pulled a 626 636 along with the 629 but that's because trans was not up to temp and likely because I started it without the harness plugged in to see what the results would be to confirm if I had it seated all the way.

I'm beyond frustrated :S

 

Guys,
I found the entire KOEO test for this. Its the technical diagnostic to rule out the solenoid, the harness using voltmeter with a jumper still in the obd connector.
It took me a while to decipher it. I'm going to run the entire thing start to finish starting at solenoid pack for voltage spike in test mode using the gas pedal, then again check the entire harness for cont/short and if it's not any of those and volts and resistance are in spec then the actual ford technical diagnostics says "replace PCM".
I'll report back.

 

glad you found that, maybe you can get it resolved, is there a link to test procedure