torque converter lock up issues

For some reason, my 95 4runner is randomly kicking out of lock up at highway speeds. I've been doing some research and have come to the conclusion that its either wiring, and loose connector plug, or the solenoid in the trans valve body.. Any feed back would be very welcome. This trans has been rebuilt and if its gonna need it again this old man is going to a manual...

 

I was having some issues with transmission kicking out of OD, finally I ended up removing the manifold with all the sensors that is on back of engine behind intake manifold.
Hard to access it, but only 2 nuts to remove it.
The ports that have the coolant U shaped hose was plugged, this affected the sensor temperature causing transmission issues.
Not that hard to remove the manifold, mine was plugged on the engine and not the manifold itself.
I checked all the sensors with ohm meter and heat, one did not have any change so I replaced it and also had to replace the vacuum switch that had broken barbed fittings.
The sensor that was bad actually ended up getting an OEM on eBay
https://www.ebay.com/itm/352587611165
Hope this helps you out.

 

Hmm.. When this first started, I ordered both sensors. Guess I need to get them installed. I'll post back after testing. Thanks for the advice!

 

You were right! I pulled the sensor and replaced it , and the plug connector was not locking in place so I replaced it as well. I've put 50+ miles on it and have no issues. In fact the truck is running the best since I purchased it! Thanks!!