One problem related to overdrive light on has been reported for the 2005 Ford Explorer. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Ford Explorer based on all problems reported for the 2005 Explorer.
The message screen on my 2005 Ford Explorer started displaying "check transmission" while driving. A few minutes later, the o/d light started blinking and the check engine light came up. I called the dealership and was told that it is a very common issue with Explorers and specifically the 2005 model. The apparently are so backed up that it would take 2-3 weeks for my car to be fixed. After researching the problem, it seems that the design of the transmission was flawed. I'm no expert but it seems to happen around 60k miles to every one. Too much of a coincidence. I barely made it home. It took less than 3 hrs for the car to stop going.