OK, I have printed the necessary pages for everything for the plugs on both trucks except the HVAC plug, I will worry about that one after I see the truck run.Greetings Matt,
Now that I have a good grasp of what you are trying to do, thanks to all the contributors in
the GMT400 forum I can guide you to the info you will need to perform your '96 > '99 engine swap.
For what it's worth, the links for the '96 & '99 manuals didn't make the first post of that
Service Manual thread, but other members contributed them in later replies:
Reply #84: '96 GMT400 Service Manual link: '96 FSM
I've downloaded and used this manual to help others. Seems to
work and search fine.
Reply #77: '99 GMT400 Service Manual link: '99 FSM
I happen to own a '99 C2500, and have used the '99 manuals a lot,
the old "Ctrl F" is your friend, and the wiring diagrams are in Vol 4.
And to give you a taste of what you will have to work with, there are 3 attachments to this:
* 1st attachment: '96 FSM Diesel PCM Component Location
From that diagram, I figured out that C200 is the name of the connector in question.
* 2nd attachment: Check out the '96 C200 16-pin pinout diagram (for Diesel)
* 3rd attachment: Here's the '99 C200 23-pin pinout diagram (for Diesel)
If I were in your shoes, I would download both, print out the relevant pages,
create a detailed punchlist/checklist, and only then migrate from one harness
to the other. NOTE: I'm not fully up on the Diesel PCMs. Are they identical
part numbers, or different? The reason I ask is that IF they are different you
need to decide whether your truck is going to remain true to the '96 Manual
and migrate with that in mind. Or are you going to move your truck to the '99
Manual? If I'm not mistaken, starting in '98 the VCM (and PCM?) monitored the
fuel system more. (In order to better implement evaporative emissions testing
as part of the more stringent EPA requirements? I could be on thin ice here. :0)
The point is that you need to answer this first, and then plan your wiring harness
transplant accordingly. (I'd think that you would want to remain in '96-land, but
by doing so you need to chase down the implementation details so that you know
what *must* be implemented, and what '99-era wiring is not relevant and can be
dead-ended.)
Q: As a baseline, were there -0- codes and the SES light was out? Or was there
a noise floor of a handful of persistent codes and a solid SES light prior to the swap?
The reason I ask is that I'm hoping the former, so that any 'false' errors from the
wiring swap will stand out and be easier to sort out, as opposed to trying to figure
out if there's leftover issues in the engine bay -or- a wiring harness merge mistake...
or even an issue with the new powerplant/transmission?
Hope you find this helpful. And welcome to the GMT400 forum!
Best of luck with your project to keep this truck on the road.
Cheers --
It appears everything on the 96' 23 pin plug C200 will connect to the 99' C200 plug A-S which is great. I will need to figure out what to do with the additional pins "T,U,V,W" from the 99 trucks harness as I do not have a place for them to connect.
I also see that everything from the 10 pin plug C204 on both trucks will connect without issue. Also good!
I have hope!