My car died a few days ago and I've traced it back to the 15amp engine fuse under the dash. I've unplugged every fuse in the fuse box and as soon i turn the ignition to "ON", the 15amp fuse pops. Reading the wiring diagram is like some foreign language.
I'm guessing it's an exposed wire, but can someone give me an idea where to start?

Any help appreciated.

 

The engine fuse feeds the triggers for stuff like the fuel pump relay and main relay. The page that's labeled "power distribution" will point you in the right direction - trace the wiring from the key to the Engine fuse, and then trace it on to the stuff it powers. I know it does the cooling fans as well, but I'm not sure about anything else (because my car doesn't have anything else).

 

What book are you referring to for the page labeled power distribution? i have been unable to find a wiring diagram for a 2002.

 

Let me know when you find the answer as I have a similar problem as well.

 

Madracki only goes through 2000, but it will get you started.

http://www.madracki.com/miata/images/wiring/00sys.pdf

 

What ended up fixing the problem?

 

Wags said JeffMan's was rear o2 sensor wires.

 

I'm gonna pull my seat and carpet out tonight and see if there's short in the wiring in there. I don't have the rear O2 sensor plugged in anymore so it'd have to be between the fusebox and plug. But who knows, maybe it got nicked when I put the seat bracket and seat in.

 

cause there's nothing on this website called "useful saved posts"

and that doesn't contain a link called 90-2002 Wiring Diagrams

and within that link it doesn't contain another link: http://www.miataforumz.com/miata-wiring.php

where you finally don't end up seeing:

2002 Miata ECU_Wiring_Diagram
2002 Miata Power Windows
2002 Miata Power Locks
2002 Miata AC System
2002 Miata Control A
2002 Miata Control B
2002 Miata Control C
2002 Miata Engine Control Systems



Nope, they don't exist. Sorry.

 

 

 

2002 SE. Mine crapped out on the freeway. Full tank. It would crank, no start. The CEL was not illuminated when the key was turned on accessory indicating no power to the ECU. I checked the 15A fuse (engine control system), blown. I put a fresh 15A in, turned the key on, blew it again.

Had to be a short circuit somewhere. Checked the O2 sensor (upstream) and sure enough the exhaust manifold heat shield had cut/burned through the wire insulation causing a short circuit. (Reference picture)

I isolated/insulated the O2 sensor wire, and she fired right up.