I wondered if anyone knows the solution to a transmission that won't go into overdrive until after the car is driven awhile?

I read where I can replace the transmission fluid and maybe even
use a cleaner prior to replacing (removes any sludge). I was guessing
it could be electrical as the transmissions are usually flawless, but the
electrical wiring is often a problem for these models. Once it kicks in,
it works fine, but has sometimes kicked out and kicks back in again.
This car has about 200K miles on it, but it is in excellent running condition
and performs well mechanically.

I'll try the transmission fluid - clean and replace the fluid; then, revisit the issue. The car isn't driven a lot, but I want to have it fully functional unless I take it on a road trip. Gold Canyon, Arizona, USA, Dennis

 

At that age it could be the wire going to the solenoid, the solenoid, the switch or the relay.
I would check for a broken wire then test the solenoid first, then move upward from there.
This is an option if you don't need low range: Automatic Over-Drive Solenoid Bypass Kit
http://www.ipdusa.com/version.asp?st...ID=0&V_ID=4410
Ed