1997 Trooper 98,000 miles 3.2 automatic

First and foremost, I live in Mexico and cannot find anyone who has the proper code reader.

Recently replaced motor with one that was for a standard transmission but they replaced some parts to make it work for my automatic.

check engine light is on and stays on. ABS and brake light comes on it seems whenever I turn to the left and then stays on. At times motor runs very rough and feels like it is in low gear and doesn't want to change out. If I stop, turn off and re-start motor it will run fine - sometimes for days and then do it again. Sometimes the same day, I have to stop, turn off and start again for everything to run right.
Also at times the battery light comes on, the a/c turns off and sometimes but not always, the car looses power and won't go over 10 miles an hour (all at the same time). Turning it off, waiting and starting again will stop this.
I decided to fill up the tank with gasoline and since I did that, I have had no problem with the battery light/ac/motor. Not sure if that indicates fuel pump prob or not.
Just had all injectors checked and calibrated. I do have a trailer wiring harness on the auto.
Sometimes the a/c is hardly putting out cold air - mostly when the car is running rough, thenother times the a/c work perfectly. At times feels like the transmission is slipping.
I know this is alot, but I need help and the Mexican mechanics are trying to figure it out, but no one seems to be able to fix it.