evo8psi23

hey guys i have a 95 miata and when since ive owned it the cel never came on ever even on key position 2. the car ran great but now it wont start it will turn on then shut off right away im narrowing it down and running out of ideas i put a meter on wire 1a got 12v with the key on and on 1b i get nothing with key on or off. i read that 1b the blue/red wire should be a constant 12v do you know what fuse that is i have a diagram that says room fuse i have no clue where that goes