Overdrive not working

So the overdrive in my GF's 95 cherokee suddenly stopped working. I checked all the fluids and the oil looked good. I did some reading on the NSS so I will try that tomorrow. Also I saw something about the TCU. Where is it located?

There is a fuse(I think)in the wiring harness that goes to the tranny module...module is behind the lower dash on the passenger side...That would cause the tranny to be kinda sluggish....Actually you will have to shift the tranny manually....Otherwise you would be taking off in 3rd...

At least there is a fuse in the harness on my 89'...Not sure about the 95'

I know my 97, every so often wont shift into OD. I somehow think it correlates to the fuel sending unit not working right(As it only does it when that sending unit is showing its butt). There is a shift solenoid, I think, that only is for the OD. I think theres three total solenoids.