s light for shifter stays on wont go into 3rd 4th need to know why ,,thx.

 

With mine (also 91 wagon) it was a bad connection at one of the plugs to the transmission. I had pressure washed the engine bay in preparation to chase down some leaks. After washing I pulled all my connections apart, blew them out with air, and applied some dialectric grease before putting back together. I had not fully connected one of the shift solenoid connections I believe (memory is foggy) and once I found that it was all good. Other than that, hopefully you'll get better info from someone else here.

 

Or was it the gear selector switch? Anyway, check all your connections first.

 

Alright, now that you think I'm crazy, I have finally remembered which connector it was. It was for one of the magnetic pick-up sensors, either the main (front) or the (counter) rear on the far pass. side of the trans. I'm just not sure exactly which one. So I'm guessing you've got a bad pick-up sensor.

Good luck
Chris