I've currently got a 1994 3.8L V6 Mustang ragtop auto which appears to have generated some sort of transmission / overdrive fault. 90% of the time the car seems to drive fine but on the odd occasion it seems like the transmission does not change out of first gear unless you back off on the gas pedal - the engine will just keep revving to max rpm unless you back off just a fraction and then it changes up a gear. It only does it on the first gear change with the auto box and does not do it all the time. The overdrive appears to work fine as you can visibly see and hear the revs increase when your turn the overdrive switch off.
In parallel with this the green "o/drive light" has started to flash when driving the car. I am not sure if this is a related problem or a completely different fault.
Has anyone experienced any problems like this with the Mustang autos or has anyone got any ideas what could be wrong?