Auto Parts: Over drive warning light?, toyota 4runner 4x4, toyota 4runner

Question
I own a 1990 toyota 4runner 4x4 with 151000 miles. And recently the over drive warning light would come on when i start to drive the car then go away after a mile or so. But now the light continues to flash continously. I can feel the overdrive working fine though when i engage it or disengage it. could this maybe be a bad sensor or something else.
Can you please help me out?
Thank You,
Kevin.

Answer
Hi Kevin,
I would say that the sensor is going bad if the OD is still working.
Am I right to assume you asked the question about your vehicle's spedometer now going out as well?
If so we'll stay on that question to respond back and forth with and just let this one die at "yes, I think it's the sensor going out" lol.