Cummins Swap - in need of a wiring guru and a few diagrams

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iridektm

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Hey guys first time posting here but have been reading around for years. Love this site full of all types of info. Hope this is the right place to post this topic.

I have 2000 2500 GMT400 and am in the middle of a 12 valve Cummins swap. I have all the pinouts for the PCM and a Chiltons Manual which is far from great for wiring diagrams.

I have everything removed from the wiring harness, if not more than everything, and have a few questions I cant seem to wrap my head around. As simple as 12volt is, never a doubt I will end up confused.

Here is where I am at on the PCM side of the wiring

RED connector
Pin 23 - Yellow - Engine Coolant Temp Signal.. Is this just for the PCM to know whats going on? This wire came off of the thermostat housing. The wire from the sensor is still in tact and goes straight through the firewall. I believe this is the only wire I need for temp, correct?
Pin 25 - Dark Green - Fuel Tank Vacuum Sensor Signal.. is this needed for the pump to operate properly?

BLUE connector
Pin 15- Y/B stripe - VSS.. this was tied into the ABS which I have removed. Does this need to tie in anywhere for the speedo to work? I still have the VSS sensor wires intact going into Pin 29 and 30 on the BLUE connector.

GRAY/CLEAR/WHITE connector
Pin 7 and 8 - Input Speed Sensor low and high.. These I believe came from the automatic transmission. They are cut, but unsure if they need to be spliced anywhere.
Pin 9 - White - Ignition Control Module.. I assume this is for firing on the 5.7
Pin 12 - Gray - 5 Volt Reference.. another ???? Looks like it may be in the same loom as the Fuel pump vacuum signal

Also looking for pinout diagrams for the passenger and driver side firewall connectors. I know I have stumbled across them a long time ago, but all the ones I find now are for pre 98 trucks. Another wiring diagram I am struggling to find is the ABS.

Dropping the motor, trans, tcase and one tons under it is a no brainer for me but Id really like to get this wiring all sorted out while the engine bay is empty and easy to work in.

Thanks in advance!
 

iridektm

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I found the C100 pinout on this site with some hard searching. Still looking for the C200? and C203? connectors!
 

rolla711

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Could of swore someone posted a whole list of our wiring diagram


Sent from my iPad using Tapatalk
 

iridektm

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You are probably right. I found the C100 which has been posted many a times. I just purchased the alldatadiy.com for my truck to help with this process and give back to anyone else who needs help.

I am trying to locate all the wires the come through the P100 pass through grommet and the P101 grommet. It looks like I will have to sift through every wire on alldata since there grommet page is empty for my truck. I know the AC blower hot wire comes through so I looked at its diagram and it has P101 labeled, but man thats going to be a task tracking all that down. Anyone already have this info compiled?
 
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