Volvo Repair: 1993 Volvo 960 Overdrive not kicking in, 1993 volvo 960, volvo 960

Question
Hello i own a volvo 960 year 1993 and i have not been able to ge the overdrive working. It's been about a whole year without overdrive and with oil prices and i now have a steady job it's given a concern to me. I read here that it could be several problems like a solenoid not actuating when it should. How do i find these problems, diagnose it and repair?

Answer
Is the arrow light in instrument cluster stuck on?Could be just a relay.Press the button on the shifter,can you hear a clicking sound from the transmission? Does the light turn on and off when you prss the button?If the light will turn off/on and there is no clicking sound, check the wire that goes to the solenoid...they will short at the back of the transmission.If that is intact then it is a bad solenoid or possible internal transmission problem