service engine soon light stays on

Hey, hows it going, my problem is my service engine soon light stays on and when I try a code reader on it, it does not do the flashing thing. I tried jumpering the 2 spots and still nothing, any ideas as to what could be going on? Thanks, any help is appreciated(the car is an 85 olds delta 88 with the 307 in it)

Stacey