Volvo: 1989 olvo 740 GL transmission problem, brake light switch, volvo wagon

Question
I have a 1989 740 GL Volvo wagon with automatic transmission. The manual override button on the shift lever is stuck on, thus preventing the transmission from shifting into 4th gear. I have never needed the override, so is it possible to disconnect this feature?

Answer
Hi Michael,the shift lock is electronically controlled by the brake light switch(after you switch on ignition),the problem could be either the brake light switch or the shift lock mechanism(below the level),it is possible to remove the lock located under the shift level,there is possible also faulty relay for the overdrive which prevents the transmission from shifting into 4th gear,it is located behind the ash tray(white )