The ASD relay is VERY important to the Jeep. When it powers up, it supplies power to the fuel pump and the ignition system (coil)
The PCM grounds one of the 4 wires when it sees a RPM signal from the Crank sensor.
Quick test: Swap relay with similar one, see if problem is fixed.
Another test: Key on, ASD relay removed. Check for power in each of the 4 pins of the relay socket. Use a test light or Meter set to volts. There should be power on 2 of the pins. The other 2 are PCM ground wire and supply to pump and ignition.
edit: To answer your last question in the original post: If you ground the wire yourself, the pump and ignition will power up, but, if the PCM doesn't see a signal from the Crank sensor, it will not pulse the coil or injectors. So, grounding the relay yourself will not fix the problem.
I start what I finish!
Last edited by Curly5759; 03-18-2010 at 12:00 AM..
Reason: more info