1994 626 mazda xl hold light is blinking

It's a sign that there's an electrical problem in the transmission (or bad sensor data.) Plug in a code reader and it should tell you what's wrong. You may need to read it manually depending on if your car has a code reader, given it's year. To read it manually I believe you count the number of flashes on the hold light, before a longer pause. It could have more than one code, in which case it will give one code, pause, then give the next and continue eventually looping back to the first code.