Yes, I have a suggestion.

When the OD OFF light flashed one or more error codes are stored in the computer. With the codes I can make an educated guess at what's wrong. Without the codes all you can do is buy parts, throw them on, and hope for the best. Once the codes are stored they will remain in the computer's memory for about a month after the last time the light flashed. If a mechanic tells you they can't read the codes because because the light isn't flashing find a better mechanic.