There have been quite a few "Why won't my car start!?" issues lately, and I wanted to address this common problem since it's only going to get worse with age. Basically there's only a few things that could prevent your car from starting.

Obvious: Dead battery, dead starter, dead fuel pump, sparkplug wires. These are easy to troubleshoot, so do them first.

Less Obvious: Blown engine fuses, key interlock, broken ignition switch, bad coilpack.

Really Annoying: Fuel pump & ASD relays, broken or shorted wiring, bad ECU, bad Crank sensor or Cam angle sensor.

Only the 95's seem to frequently have bad ECUs, due to a ground trace defect. The easiest way to know you have a bad 95 ECU is if the car simply shuts off while driving, but will start up again if you wait a few minutes.

For other years, it's often just a bad relay. These relays are mechanical parts that will wear out over time. They're located on the driver's side of the firewall, near the brake fluid reservoir. The Chilton's manual contains actual tests you can do on them with a voltmeter.



From left to right, we have:
Fuel Pump relay - Simply turns the fuel pump on and off.
ASD/ECU relay - "Automatic Shut Down" controls the power going to the Fuel Pump, Ignition/Coilpack, and the Injectors.
ATX relay - Used for limp-home mode?
ATX Reverse relay - Switches on the reverse lights when the automatic transmission is in reverse.


Here's some related articles if you really want to know how the system works:
http://www.automotivetroubleshootingsecrets.com/September_2002_ATS_ezine.html
http://www.off-road.com/jeep/tech/4lswap/wiring.html
http://minimopar.knizefamily.net/ecu/index.html

if the asd is out will the car still have spark or not?

I'm not answering dumb questions that have already been answered. Not even from 95eclipse420A.