TRANSFER CASE VACUUM HARNESS

[Iron Duke II]

I am attempting to swap out the transfer case vacuum harness purchased through Geno's Garage. Does anyone here know what the intended purpose is for pictured fitting on the green line that should go to the firewall distribution vacuum line?
https://www.genosgarage.com/product/dodge-ram-transfer-case-vacuum-harness-52078361/transfer-case
View attachment 128872

 

[BigPapa]

That’s a check valve or an air vent filter.

 

[Iron Duke II]

That’s a check valve or an air vent filter.

View attachment 128875

The green line from the transfer case control switch is currently connected to the firewall distribution vacuum line as is the white line from the transfer case control switch. The diagram you generously shared clearly displays an air vent on one line and a check valve on the other. I presume the green line should be for the air vent filter and the white line is the primary vacuum line from the firewall to the transfer case switch? There does not appear to check valve on either harnesses.

 

[Iron Duke II]

This appears to include a discussion that covers the issue.
https://www.cumminsforum.com/threads/transfer-case-vaccum-switch.341326/

 

[BigPapa]

I don’t know about the colors and I’ve never owned a 4x4. Sorry.

 

[Iron Duke II]

I don’t know about the colors and I’ve never owned a 4x4. Sorry.

Thanks for the input. It helped solve one of the issues. The vent filter line was attached to the vacuum system on both ends. Now the 4wd light comes on and I got the 4wd into 4 Lo.The truck was in a local shop to do a cleaning on the exhaust brake and a few other things in 2019 and sat through most of 2020 until a few months ago. I suspect that shop connected the line to the vacuum system. I discovered they line was connected to the tee meant for the cruise control.
I rarely engage it. Last time was in the snow near Parks, AZ. back in 2018.

 

[Iron Duke II]

Swapped out the Transfer Case Vacuum Switch and the whole Transfer Case Vacuum Harness while under there. May it will go another 25 years.