Transmission works fine except will not go into overdrive. Toyota truck owners manual says engine temp must be above 122 degrees F. and must not be in altitude above 4000 feet, otherwise the overdrive will not work. Overdrive has never worked since I bought the vehicle used. Overdrive indicator light will show "Off" but does not light up on "On". I suspect electrical problem, possibly one of the above mentioned sensors. Where can I find them and check for any other problems? I do not know the type number of the transmission, but it seems to be identified as conventional automatic. Local Toyota dealer refuses to help. Says he can not get a motor home into his shop. Obviously he can, but just does not want to fool with it. I would appreciate help with my problem!
