Hi Guys,
I've been an occasional lurker here for quite a while, the PDFs linked in the FAQ have been damn helpful in my troubleshooting as have several threads on the dreaded no start gremlin.
My Dak has been lurking in the weeds for quite a while waiting on me finding enough time to straighten this out, the old girl cranks willingly but that's as far as she'll go, I get the initial 'blip' of the fuel pump but no spark and the 'key dance' returns no codes but '1255' IOW it's not getting any crank signal.
I had three of the dreaded corroded splices next to the relay box, they all had continuity but I cleaned them up and respliced anyway, one of the first things it got when this popped up was a fresh Hall Effect sensor in the distributor.
A member here called 'dodgerules86' posted a very good engine-side wiring harness diagnostic recipe back in March, I fired up the multimeter and printed off the pin-outs for the ECM today and gave it a shot.
Everything went fine until I got to pin 8 where I've got full continuity to ground, the same story on pin 9, this is not good
The rest of the engine-side wiring looks damn good so I assume I'm going to be digging into the firewall connector or the ignition switch fairly soon.
I'm open to suggestions and advice at this point....

 

Welcome to DodgeForum!

Can you tell if the coil is getting power? If it is, I bet its the crankshaft position sensor.

Also, code 12 is the beginning of codes and 55 is end of codes, so nothing wrong there.

I don't have the pre-magnum computer pinout on hand, so can you please say what pins 8 and 9 are supposed to do?

 

What is the #9 #8 pin for? The computer does need a ground input, those might be it.

 

Thanks for the welcome.
The Hall Effect sensor in the distributor is all the crank sensor these pre-magnum engines have.
At least I know the computer isn't dead
#8 is battery supply for the ASD relay and #9 is the ignition feed, neither one should have a path to ground with the ignition switch off.....

 

So if two power feeds are grounded out, why do you say "At least I know the computer isn't dead"? I don't think I'd rule it out at this point!!

 

You're right, I probably can't...
Todays adventure was checking continuity from the ECM connector to various components, once I figure out where the shunt to ground is and correct it maybe the computer will tell me something useful
After further thought, I replaced the ignition switch about a year before the starting problem came up, while the box said NAPA/Echlin the switch said Made in China, I'm inclined to see if yanking the ignition connector does anything interesting over on the engine side.

 

Don't be shy about going back and checking your work, it turns out the steel 'dish' for the hall-effect sensor broke its plastic bushing immediately after I changed the sensor, explains no crank signal, it was laying loose in the bottom of the dist.
A rebuild distributor got the old girl back on the road, another issue has since popped up, new post forthcoming.