Why are my transmission wires spliced?

[4ranover]

A few weeks ago, my new-to-me 2000 4Runner threw a P0773 error code (Shift Solenoid E Electrical), which could be a faulty solenoid, but also faulty wiring or connector. Since then, the check engine light has turned off and come back on it's own, several times.

Today I looked underneath and saw some interesting work. The service history is fuzzy, so I'm playing detective trying to figure out what's been done. Right now I'm thinking either the transmission or transfer case has been replaced at some point. The transmission is a 340F (or at least it should be) and not sure about the transfer case. 120k on the clock when I got the truck last month.

Transfer case wires have been spliced:

https://flic.kr/p/MMJbsa

Transmission (solenoid?) wiring appears unmolested, but hard to be sure since the wires themselves are concealed. The two black wires and plugs on the left go into the trans:

https://flic.kr/p/MVaGbF

Shoddy stacked washers on these nuts (I believe mating the transfer case to the trans):

https://flic.kr/p/Mt4ELj

And lastly, the trans wiring is hanging all over the place, not really secured anywhere:

https://flic.kr/p/LXE9Wd

At the very least, the work that was done was sloppy. I'm hoping that's the extent of it, and there's nothing super concerning here. The splicing is what I'm really wondering about.. perhaps the transfer case was replaced with a non-stock model with different connectors?

Thoughts?

 

[rkntoy]

Looks to me like someone quickly swapped in a junkyard tranny/t-case.

 

[4ranover]

Looks to me like someone quickly swapped in a junkyard tranny/t-case.

I'm not experienced with junkyard swaps.. is there a dead giveaway here, or are you basing that off the shoddy work?

 

[St Runner]

Almost no one would climb under there and pull that harness loose. It is normally secured on top of the transmission. The splice could be from not disconnecting all the plugs before dropping the transmission and the stacked washers are almost a guarantee that some one took off the transfer case as normally when you pull the transmission you do it as a unit. Everything points towards the transmission being pulled for one reason or another. Since its an auto, I would guess that the transmission itself died and someone pulled it and replaced just the transmission and reused the transfer case

 

[rkntoy]

I'm not experienced with junkyard swaps.. is there a dead giveaway here, or are you basing that off the shoddy work?

Many times when you get trannys or tcases from a junkyard they end up cutting the wires to all sensors and leaving them with the unit. I have seen people cut and splice like that when the plugs are different or one guy even said that splicing was faster than pulling the sensor unit off the existing unit.