Hey,
I have a 92 F105, 5.0, AOD
Rebuilt motor, trans, and rear with less then 1,200 miles on them.

The rear main seal was leaking, for the warranty of the motor they wanted it fixed asap. Took it to a shop (wasn't too comfortable doing it myself, but I do most of my own work).

When I went to pick up my truck at the shop, as soon as I started the truck the check engine light came on with code 61. Figured it was odd, talked to the shop manager, they were no help....

So I drove it home and did a resistance check on the ECT, came out of spec by a bit. I did get 4.60V at the plug when checking for voltage. Figued easy enough, sensors do go bad after a while. Replaced the sensor and started up the truck, was running great with the engine light being off. I shut off the truck to put the air tubes back on and cleaned up my tools before I took in on a test drive. Soon as I started back up the truck the code tripped again, and the truck was really running rough. Only when the truck is warm that code seems to trip.

I was wondering if someone could help point me into the right direction, I took of the main wiring harness to inspect it for damage but I'm not seeing anything. Not sure what all sensors share that same circuit.

Any help would be greatly appreciated. First time I've seen a code 61, and haven't seen too much on the forums about just this code. Thanks!