Gs 300 '95 Overdrive Indicator Light

[susienewone]

My 1995 GS 300 that has 198,000 miles (well maintained miles) recently received a new battery and immediately following the installation (literally about two blocks away from the dealership) the Overdrve "Off" indiator started flashing. Knowing that disconnecting the battery can cause this the car was returned to the dealership and was told it wasn't the battery. However, they did offer to spend three hours of diagonstic service at a cost of $400+ dollars to determine the cause. My question/s, has anyone experienced this flashing light and is there another place in the Houston area that comes recommended? I am the original buyer/owner and the car has always been maintained at a dealership but that $400+ seems a little excessive. Thanks to all.