I checked the white fusible link. There is power to the ASD relay, and to the PCM. It seems like the fact that the CEL quits working when it doesn't start should be significant. I've Googled it and haven't come up with anything.

 

Found this on allpar.com According to this, the ASD relay is ok, and there is either a problem in the wiring or the pump itself.

 

Again, I found this on allpar.com. What caught my attention was he mentioned CEL light didn't function during no start condition.

[/QUOTE]Summarizing, my key symptoms for dead PCM were:

• no check engine light with ignition on and engine not running.
• no check engine light codes by toggling ignition switch on-off-on-off-on within 5 sec.
• no +8V at the hall-effect sensor (ignition pickup)

YMMV, but my troubleshooting from no-spark went ASD --> Ignition Coil --> PCM:

1. Confirmed no spark by holding coil output wire near ground while cranking.
2. Confirmed no voltage at coil +.
3. Confirmed no fuel pumping by listening to tank when turning key on.
4. Disconnected coil + and confirmed no short across terminals.
5. Confirmed fuel pump OK by jumpering 12V to coil + and listening to tank or throttle body.
6. Following up on no-spark, confirmed ASD functional by grounding its PCM side. (PCM activates the ASD by providing a path to ground).
7. Checked 3-wire ignition pickup connector for supply voltage and found it only 0.7V versus normal +8.
8. Confirmed all ignition wires good from pickup to PCM and ground. *** PCM is bad ***
9. Unlikely, but the ignition pickup could also have been bad. On vehicle test would require an external 8V supply, but I didn't have power nearby.

I had the service manual (and good guidance above) for this. At a minimum you need the connector pinouts for the ASD, PCM, and ignition pickup.

Finally, reman on these 90s vintage mopar PCMs is apparently not very extensive ... 3 electrolytic caps and possibly a diode or two. DIY is possible in a pinch with decent electronics skills....should reman or a yard PCM be unavailable.
[/QUOTE]

Here's the link to the page for the full discussion. https://www.allpar.com/forums/thread...-other.169740/

 

there are more fusible links than just the group that are together. there is a a white one in the harness between the orange one and asd relay.

 

Thanks for the info, Crazeywolfie. I'm pretty sure this is not a fusible link issue, I have checked these several times. I thought I had the symptoms nailed down, and then they changed. As I said above the, crank no start was indicated by no lamp test of the CEL when the ignition was first turned on, and not being able to display stored codes. I removed the 60 pin connector on the PCM so I could back probe the wires. So with the PCM reconnected, I tried restarting which it didn't, but now the CEL comes on. Go figure. I called it a day. Today it starts, so I'm on hold again. When it fails again, the plan is to check pin #9 for batt voltage, pins #6, and #7 for 5/8 volts respectively, and check for pins #4 and #5 for voltage drop. Anything to add to that? My trouble shooting windows are very short sometimes, so I need to be prepaired.

 

Over a couple of troubleshooting sessions I have checked the following:

1. Measured voltage drops across all the fusible links. The highest reading I got was .03 volts.
2. Measured voltage drops across grounds, pins #11, #12, #4 and #5; highest was .04. Some were 0vdc.
3. 12 vdc at red, at ASD, 12 vdc w/key on at dark blue.
4. Grounded ASD output to check function and 12 vdc at dark green/blue (coil, fuel pump, injectors)
5. 5.2 vdc at PCM pin #6, 8.4 vdc at PCM pin#7, and 8.2 vdc at connector at distributer pickup.
6. Checked voltage at PCM pin #24, and connector at distributer pickup. 0 vdc when engine cranking.

My last check, #6, should have been a pulsating 8 volts, correct? Unless I missed something there are only few possibilities; the Hall Effect pickup in the distributer is bad, the circuit that grounds the sensors to PCM pin #4 is faulty, or PCM internally at pin #4. Can I directly ground the sensor ground circuit to check? I also disconnected the Map sensor, to see if that made any difference, it didn't.

 

Id use a voltmeter and check your battery to see if it has 12v in the off position from there check your terminal connections if sitting for long periods of time you might want to disconnect the battery if you can charge it and get it to run it tale the volt meter and check the volts coming in to the fuse panel in your engine compartment make sure its getting 14 to 15 volts and make sure the battery is too while ots running if not getting the full juice to battery check the fusible link it should be the first fuse to the engine fuse panel where the negative amd positive come from the battery and altI spent hundreds of dollars getting a new battery and alt and tearing all the wiring apart to the pcm and distribution cap just to find that the Fusible link was broken and thats why the battery was draining and causing it not to crank after running and sitting overnight 5 dollars at an auto parts store and my cel no longer comes on