So ive owned my 93 miata for about a month or so now, havent driven it much due to it needing a tune and waiting on tuner to be free. The few times i drove it it ran fine outside of running rich, i finally got it tuned last night and everything was great until i got home(about 25mins later). I got home and the car wouldnt shut off, took the key out and it was still running(ran fine just wouldnt shut off). i stalled it just to get it to shut off, but then with the car off and key out the lights on the cluster (maintenance lights when you turn the car on, airbag engine light etc) stayed on, as did the gauge lights( boost and afr gauge) and the fuel pump. putting the key in and turning it the radio and interior lights cut on, and cut back off taking the key off but the other things do not. what would be doing this? people are telling me ignition switch, or the main relay, could it be one of the two or something else?

 

Have you tested those two things yet?

 

Yes.

 

Pull the main relay and check for continuity across the switch pins. There should be none - if there is - relay sucked. If there is not - likely ign switch sucked.

 

Ignition switch failed or check that the electrical connector/switch is still mounted to the ignition cylinder still on the rear by removing the knee guard panel. There should be a small cadnium plated screw holding the Ign switch to the cylinder body, and should have a slight wiggle. Same scenario happened to my friends cressida last week and the switch had came loose from the cylinder and wasn't being switched by the key.

 

i've replaced relay and ignition switch, neither of which worked. any other ideas?

 

i replaced both with no fix.

 

You say you got it tuned. Does that mean you are running a standalone? Is it a MS? Did you remove the st sign fuse?

 

yea ms pnp2 fuse is out, i think i may have found a problem, not sure if it is the main problem but could for sure have something to do with it. looks like someone messed with the main ground under break booster, and did a super **** job putting it back. i kind of wiggled it and seemed fine, but didnt mess with it long since it was pitch black out and i dont have a garage. but went out this morning and it pretty much pulled apart barely pulling it.