no speedometer since t-case swap, and will not shift?

So you have the VSS wiring connected to the transferase sensor, also there is a VSS in the transmission as well that is used while the 4wd is not engaged. So, both need to be wired correctly, here are the wiring diagrams so you can double check your work. Check out the images (below). Let us know what you find.

if you're speaking of the purple/white and green/black wire, which is shielded, yes it is intact, as well as after making and installing a temporary test wire, (prior to opening up harness to inspect for any damages) to verify that the sensor was working. how would i legitimately test this sensor if needed? if a second sensor is "in" the transmission, are you saying internally? or plugged into the transmission case? i see a.

Sorry I was mistaken, there is only one VSS, my bad. It is in the tail housing of the transfer case. You can unplug it and use a voltmeter on millivolts and then spin the driveshaft and you should see voltage generated.

its a new sensor, tried that, seems to be good!

Okay, then the sensor is working. I would test the wiring between the sensor and the PCM, here is a guide to help:

https://www.2carpros.com/articles/how-to-check-wiring

Use the wiring diagrams above to see which wires to test and where in the PCM wiring connector they are. Let me know what you find.

audible tone/ continuity showing good on vss harness

So the wiring is good between the VSS and PCM? I would use a scanner to check the VSS output to the PCM while driving. This will help determine if the problem is before or after the PCM.

been busy, but will get a proper scanner to run the test and report back!

Yep yep, I appreciate it. Have a good Sunday!

scanner, as in an obd2 scanner? would an Ediag elite scanner work on this? its a bidirectional/ active test one.. or, are you wanting me to probe the pins on the vcm connector?

Yes, that scanner should work. See if it has an option to see vehicle speed.

Okay, so after initially thinking there were no codes, this dongle code scanner is showing a lot of issues, and there's still no check engine light. There's power to the transmission, but I've never seen anything like this before. The vehicle doesn't have catalytic converters or O2 sensors (previous owner). What I can't understand is that it shifted with the incorrect transfer case, but only had trouble getting in and out of overdrive.. im guessing the trans was on its way out? or did something happen somewhere accidently? just bizzare. no vss action still while driving etc. i drove it around the yard, and took a short recording.i have came across broken wires etc and its almost like im chasing a ghost. rebuild/replace all harnesses? or junk the truck? haha

Wow, you are not kidding, it looks like many codes, like the PCM has a bad ground or the vehicle needs a rebuild PCM, this can be your problem. To recap, you have checked the wiring to the PCM, replaced the sensor and the speedometer still does not work and the PCM cannot see the vehicle speed correct? if so I would check the PCM grounds and power inputs and fi they are okay swap out the PCM. Here is a guide to help and the PCM connections so you can test them.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the images (below). Let us know what you find.

so far, the c3 (white/ clear connector) pins 17 and 18 aren't showing anything. the rest check out good. the pink wire in c1 pin 4, doesn't even exist. which i did notice on the schematic i have, which is normal. you may have shared a schematic to a different year. we are definitely on the right track now lol.. i did a little further investigating myself, ground circuit 451 (c3 pin 17,18) goes to g103 and g104. 104 i have cleaned and reattached 2 weeks ago. which became a handy ground location while doing these latest tests. the 103 on top shows good to the battery, i also noticed the MAF sensor ground/ signal and the ignition control module gets to the vcm on that same harness, so ill check the sensors out. could a MAF or ICM cause all these codes and showing no ground? ill report back shortly. if anything else comes to mind on those 2 c3 vcm grounds, let me know! thank you

What codes are you getting?

all the same ones, pop right back up

they're in the video i sent yesterday. if i clear them, they come right back on the scanner not a minute later.. no check engine light on the dash, but they are showing on the module scans..

and more, ill check

That is a lot of codes, its like the PCM is bad, I would try to get a replacement and see what happens, you can also send the old PCM in for testing.

I did mention in the beginning, that I tried that, relearned it, kept the same eprom etc. Same results :/.... im wondering if a different year harness with a different pinout may be a possibility? What about the pin 17, 18 grounds you had me check?

what confuses me, is that i have found a plethora of broken wires, corroded connectors, grounds on top of fresh paint from whoever "attempted" a half-assed restoration. All of this has been addressed, and absolutely nothing has changed. from turning the distributor once loosened, to get the timing dialed in for an "on dash" check engine light, the light went off. been off since. but scanning shows codes from everywhere. the only other difference is, the trans is actually getting proper 12.5v voltage at pin E (pink wire) as when i started, it was down to around 5v... yet still, all the symptoms are the same. (no speedo, wont shift) i can manually shift with almost no feel, but it is shifting, up to 3rd.. and of course, down shifting manually works as well down to first. lights all work, every gauge works, but the speedo... i always disconnect the battery for any electrical work. bizarre, isn't it?

Yes, this is strange, I would guess the PCM has shorted out due to the wiring issues. I would try another one.

as i just stated eariler today, i did that already.. i understand and appreciate you trying to help. ive owned several of these 96-98s, and have never encountered anything like this.. it would be quite an accomplishment to solve this issue, with how much i am already invested in it, as it seems rare and impossible.. i want the satisfaction of it getting figured out lol. could you help me with what i should do next?

There is the wiring, power, ground, the sensors and the computer and you have checked and replaced everything correct?

yes.

you had me test the pins 17 and 18 (vcm grounds) on c3? i did. not showing anything