Isuzu Repair: Isuzu overdrive transmission, overdrive transmission, isuzu trooper

Question
QUESTION: I just bought a 1988 Isuzu Trooper with a 2.6 engine, with automatic, push button overdrive. It shifts in the first 3 gears perfect, but won't shift in overdrive. Where do I start looking?

Thanks.

ANSWER: Well it depends. It could be lack of fluid, dirty fluid, clogged tranny filter, burned solenoid on transmission, or binding linkage. Is the detent cable properly connected and proper amount of fluid in the transmission Tony?

---------- FOLLOW-UP ----------

QUESTION: I checked the fluid and filter and that's fine. The detent cable is where the books says it should be, but I don't know about the solenoid is. Where is it and how do I check it and if it's bad where do I get a solenoid?

Thanks for helping,
Tony

Answer
So the vehicle never automatically shifts into overdrive? If that is the case than it could be a number of things to be honest Tony. if there are no fault codes or a transmission light illuminated than it could be internally(slight possibility) Although the O/D switch might not be sending a signal to the transmission so the switch could be bad as well. Although I will be looking around in the meantime and give you a more clear answer okay? Thank you for your patience as well Tony.