You might want to replace the regulator. They are cheap. Erratic voltage will make the TCM go crazy.

 

^thanks will do!

now-which is my regulator? 1991 F350

A) http://www.ebay.com/itm/ORIGINAL-ENG...ht_1020wt_1163

or

B) http://www.ebay.com/itm/ORIGINAL-ENG...ht_1241wt_1163

 

1991 should be (B).

 

Woooow...i couldbhave save myself 40 hours and 250 bucks in sensors and fuel and frustrations.
17 dollar part, plug n play. Volt gauge solid as a rock.
Ive never felt the trans shift so smooth. I barely have to dip into the throttle.

Dont think im grtting any tc lock right now as i took it to 100 and was at 1900,
but trans is shifting great-however i still cant manually lock the converter by grounding the trans side purple wire..



Edit: ***, trans just went into limp mode out of nowhere. Might be its freaking the tc is t locking. But still cant lock convter manually

 

1.clear the code.
2.connect ALL the wires back to stock to the solenoid pack.
3.drive the truck.converter may not lock up until a couple miles if she's cold.

if no luck,test the TPS now.your probably going to find it needs to be readjusted now that you fixed the voltage supply.
your meter still finding a dead spot? - this must be fixed or - limp mode/code 62/no lockup.
4.swap to the 3G alt sometime and be done with that old school issue.

it sure sounds like your making progress now.

 

unsuccesful yet again.
Tps confirmed to be fine, no deadspots.
When pcm is rest all is dandy. Usually 10-20 mins it trips. Reset pcm-everything good again. Repeat cycle.

Grounds good, system voltage good. I got no clue now

 

eec relay still good?

 

^^ where would that be? and is there a way to test it?

Im going to head to parts store tomorrow to print of all the electrical diagrams for this **** so i can actually start testing wire connections

 

not sure where it is on the '91.on the 92-94 it's in the power distribution box under the hood.
your trans is getting power,but maybe the relay plugs are corroded and not sending full voltage through.i know mine looked a bit shady lol so i cleaned 'em up and greased and plugged her back in.did it to all the relays in there while i was at it.you get to 20 yrs old,and electrical connections are not as nice as they used to be.

 

^ you know that might be it as i was only getting approx 6-7 volts when unlocked on the purple wire and it should be 12-14. But doenst explain why it happens only after certain amount sof time driving. and as soon as you reset the pcm (everyhting is still hot to the touch) its back to normal..
but then again,when i ground TC i see 0 volts yet it doesnt actually lock!

 

They'res (part) yer problem. Batteries arent getting charged at all. Explains why it ran great for 20 mins when switched over (old regulator charged batteries), then started losing voltage.
With truck running batteries measured at ~11.9, slowly dropping. Didnt have time to test alternator or other connections with new regulator, pouring rain out.
Getting close/

 

ahhh.3G upgrade time.say goodbye to that old school alt and its troubles.$15-20 bucks and done.
https://www.ford-trucks.com/forums/1...3-92-idis.html

 

^eventually will do that, but for now im hoping to just fix what i got.
need to measure alternator voltage first to see if its actually even sending anything out, or is the regulator cutting it off prematurely.

 

went to measure voltage, no charging.
everyhting is wired same as this


I noticed the yellow wire was badly corroded and ripped clean off. Ok reinstalled it, all connected still no charging.
I probed the green wire as it should have 12 v KO, i got zero with the new regulator.
Figured what the hell, plugged old regulator back in-boom 12 volts at the green wire KO. So what the hell is up with me new regulator?

Drove around, all was good, batteries getting back to 12.6. Truck was running for 20 minutes, pulled into a parking lot where i idled for 10 minutes and noticed the volt gauge quite high (by the "a" in normal) when on the fuel to move around the lot (also noticed slippage then) and dropped to "M" when idling. Strange-this only started happening when **** got warm.
Ok being an optimist-its the old regulator failing and heating up too much...but they the frig is new regulator not working? Could it be bad from new-and if so-is there anotehr way to test it?

 

Also, there seems to be a wiring information conflict:

above diagram:
I-green (signal wire hot in run)
A-yellow (rectifier)
S-White (stator)
F-black (field)

What Video says:
I-(should be green), instrument cluster light
A-yellow, alternator (hot all the time)
S- green/w yellow-Signal On line
F-red, field

What I have
I-green (12 v KO)
A-yellow
S-red
F-white

Havent taken off loom to see where what exactly goes, but something screwy going on