Yes, a light bulb does precisely this. Also, at one time you could purchase a little device that looked like the bottom part of a light bulb with an electrical socket in the other end so you could...
The reason it flashes is because the 72 pin connector is old.i would recommend getting a game genie or get a new 72 pin connector . they have them on eBay and on amazon for like 5$-20
Replace the speed sensor on your rear end, dont wait too long or your spedo will start to go bad!.....If a computer is hooked up it should retrieve stored codes. it could be anything from a wiring...