98 12 valve cummins no bus, need help please

[Great work!]

I would say you already did all that with your troubleshooting.  Do check your battery voltage while running since you did an external regulator. High voltage can ruin it.

[KyleM94]

I have an in cab meter thats in my switch panel for lights its at like 14.7v when running without lights but im going yo disconnect it when i put the pcm in and see if it gives me any response before hooking everything back up. When everything was working it was at 14.5 i think 

[KyleM94]

PCM came in today so fingers crossed although im not getting my hopes up

No change so i think i should give up

[Great work!]

So after all that it still doesn't work?

 

Check for good continuity on the ccd wires from the PCM to ABS and then check continuity from ABS to cluster.

[KyleM94]

Yup still not working i will check tonight

[KyleM94]

Infinite continuity between PCM and ABS Pin 29/30 on C3 PCM and Pin 3/7 on ABS and i checked pin 29 to 3/7 and 30 to pin 3/7 just to be safe and nothing 

[Great work!]

Open up the harness over the engine and follow the ccd wires.

On a 24valve they have 3way t that goes to ECM , not sure about yours.

[KyleM94]

I had it all unwrapped and i cleaned all wiring and inspected it all ill have to look at it

[KyleM94]

I put the pcm back in this morning i have it just sitting with on screw holding it loosely for now i turned the key and the OD light isnt on anymore i have the ESS un plugged im gonna purchase a new one and gap it when i get a chance but the WTS still is staying on very curious

[KyleM94]

So i unplugged and plugged the pcm

C3 in a couple times and OD light came back on im wondering if maybe the pcm isnt getting good connection should i use and grease or anything 

[Tractorman]

You can use dielectric grease, but I don't think it will help your situation.  The dielectric grease primarily helps keep out moisture and reduces the likelihood of oxidation on the pins. 

 

I would carefully inspect the multi-pin connectors for any spreading of the the female terminal and inspect for any wires that may be partially pushed back inside the connector.

 

- John

[KyleM94]

Ill look at the plugs and see the pins looked ok when i cleaned the harness but ill look more thoroughly at it again

[KyleM94]

I dont see any issues with the plugs on the female ends 

[Great work!]

On 3/8/2024 at 4:10 PM, KyleM94 said:

Infinite continuity between PCM and ABS Pin 29/30 on C3 PCM and Pin 3/7 on ABS and i checked pin 29 to 3/7 and 30 to pin 3/7 just to be safe and nothing 

My diagram shows pcm 28 to ABS 10 for CCD- . Pcm 30 to ABS 3 for CCD+.

 

Double check and verify your ohm meter and test leads are working by touching them together.

Open up the large bulkhead connector and check the 3 twisted pairs of wires. Look closely at both mating connectors for bent pins or spread sockets. Lightly tug each wire and make sure they are locked in to the plastic good.

 

See photo.

 

 

[KyleM94]

Will do i should be home for a but after today its outage season so work is pretty strong atm. Ill pull that plug and see whats what and check my continuity

[KyleM94]

Sorry for the gap between replies i checked those pins continuity is 0 ohms. I pulled the connector didnt see any spread pins or anything wires all seem connected good into the plastic. Im not sure what else i can do. This summer ill be pulling the dash and motor to put in a 24v and all wiring modules etc. is there a way i can run cruise control and ac without the PCM until then or no?