Tranny problems

2001 Rodeo automatic V6.
When driving home from work it started hard shift between 2 and 3 gear. Once got on highway and was fine. After about 15 minutes the ATF/Oil light came on and when turn off highway. Had problems getting truck move forward.

When I got home let truck off. Later started truck and cycle through gears and have no problem going in reverse but, can feel it trying to go forward.

Check the fluid after finding out here and added about half quart. Still same problem. Notice when shifting to 1st the 2nd light stayed on. remove and clean transmission range sensor. Now I get all lights buts problems still there.

Any ideas. Thinking about changing filter and fluid. Its been about 30 since last flush and filter change.

Is your alternator the original one? If so, have a load test performed on the alternator and see if it's holding above 14v LOADED.

These trucks & transmissions will run incorrectly if the alternator is weak.

Check your ground connections too.

About four days ago the battery shorted out had had to got a new one. Could the alternator cause that.

It's possible yes, and you could also fry the NEW battery if your alternator is not doing it's job.

I had this exact problem - new battery (2mo. old) got fried; I think it was reversing the current or a diode was overcharging? Anyway, it actually boiled acid out the top of the battery on a long trip. (Did not know until I was home and off of highway speed) Alternator was the cause....