I have a 95z28 and the check engine soon light will come on when you are driving and the fans will then come on, but when you slow down for a stop l light the check engine soon light will go off and the fans will to but only when it is in drive. This happens when the car is completely cold.

I need to code scan it OBD 1, or figure it out somehow.

 

Yup! No solution by internet without it. Visit Autozone for a free scan. post up the code(s) #'s present.