*** Most Recent Update***

First and foremost I want to@Hey You @DerTruck and @MoparFanatic21 they were a huge help and I appreciate their efforts in sticking with my until I got this resolved, they taught me a TON of things that will ultimately only make me a better truck owner and no doubt will serve me in the future in a variety of ways...

This preface is to explain what happened (or what I think likely happened which led to the problem down below. This thread is an excellent read because there is a ton of information in it to help diagnose electrical issues in a 2nd gen Ram.

it all started when I changed my plugs and put on a new catalytic converter. As soon as I was finished my truck wouldn’t start and gave a no ASD to ground CEL code and started for 1 second then died...

I then erroneously tried to start it again (cranked but Would not turn over) at which point the CEL stopped lighting up (even with key on engine off) I looked under the hood at the fuses and the 30 amp “engine cont” fuse was blown. I changed the fuse but no luck...

checked for spark and I was not getting any at my plugs. When I would turn the key on the fuel pump would prime non stop until I turned it off... I spent the next 2 days tracing ALL of my wires and connections through the engine harness to try and find a short.

eventually we as a group came to the conclusion it was likely the PCM causing my issue. But why would my pcm fry itself after changing my plugs and exhaust?

well, I read in some other threads that a short in the o2 sensor can cause some issues. And when I checked my downstream o2 plug I realized that 1 of the pins was bent and was touching another pin.

after I replaced my PCM the truck started but gave a code for transmission pressure sensor voltage. (Which the o2 sensor shares voltage with the pressure sensor or something along those lines)

I fixed the pins and changed the pressure sensor inside my valve body and badaboom badabing the truck runs again with no codes!

still not 100% sure what the original issue was but the assumption is that I didn’t pay attention when plugging in my o2 harness which lead to a short, that short popped my engine cont fuse under the hood on the first start then when I tried to do it again it fried my PCM.

so the moral of the story is PAY ATTENTION to even the smallest of things because if you don’t you can do some real damage on even the smallest of jobs!***

Original post below:

Hey all,

first off sorry to the couple people who have PM’d me in my absence. I just replied. I’ve been stuck in the UP for a couple days.

now on to my issue.
i got home this morning and decided to change my spark plugs upon doing so I realized one of my plug wires was pretty burned up. So I stopped and drove to get some new wires

as soon as I got home I finished the plugs and put in new wires and right away the truck started then died within a second.

the 30A fuse in the box under the hood was popped (engine control I think it’s called?

i replaced the fuse and it threw a code p1389 which is for the ASD relay

i swapped the ASD relay with another and still no start but this time the check engine light won’t come on. even with the key in the on position...

is my PCM dead? I’ve double checked all the other fuses... is there anything else I can test?

I’m thinking the plug wire shorted while I was driving to the parts store to get new ones and it killed my pcm somehow...

fuel pump primes but it just cranks and won’t turn over and the CEL never turns on or flashes at all

 

Also, my OBD2 scanner won’t connect... that’s the main thing that leads me to believe it’s the PCM

 

See what you are missing. Check all the grounds

 

I did even ground through rust for better contacts

I’m at the salvage yard but can only find a pcm for a 99 1500

 

Found one in a 99 the software update says 98 I’m going to buy it for $20 in the off chance it works but I think hey you already said it wouldn’t

 

The fuel pump is controlled by the PCM so if you can hear it prime the PCM is not completely dead at least. Do you have the tach bounce when cranking ? The ASD controls power to the injectors and ignition coil and the blown fuse #6 sends power to the ASD. Isn't your truck the one with the MSD coil ? I'd look closely if the ASD is actually providing power during cranking. Easiest would be with a test light at the coil +.

 

the only movement on the dash when cranking is the alternator volts.

i can feel the ASD click with my finger when turning the ignition on.

I don’t have a test light can I use my multimeter?

fuse 6 in the cab? Mine says that’s turn signal
indint have fuse numbers in the box under the hood...

and yes I have the MSD coil

 

Sure voltmeter works too. Fuse 6 in the PDC is the one labeled "engine cont" and is the one providing power to the ASD relay and from there to the injectors and coil.

My reasoning is: You had issues with the coil before, you worked in the vicinity of it and the fuse that blew provides power to the coil. So that's where I would start before swapping PCMs.

 

Oh ok! I swapped the #6 fuse with a new one and it hasn’t blown yet. I’ve swapped the ASD relay with another couple that work and that hasn’t helped.


other than testing the resistance to the coil (which I have) how would I use a multimeter to test it while cranking?

i just did a spark test with an extra plug on the engine block but there’s no spark coming from it..

(I’ve never done a spark test before so idk if I’m doing it right.) I pulled a boot and out an extra plug I had in it and placed it on the engine while cranking (picture attached)

 

Ok so I used a set of jumper cables and clipped the spark plug and grounded the other clip just to be sure and the spark plug definitely does not make any spark when cranking...