Wiring harness problem

[T3X_S13]

Okay I have a 91 240sx shell 5speed and the harness that came with the car is a auto converted 5speed.I was fixing all the behind dash harness and I noticed that the brown plug for the secondary ecu plug is missing.

Here's my question?
Does the brown plug run into the harness or does it clip on to a plug on the harness,if not are the interior harness the same 5speed and auto I been finding only 5speed harness's at the junk yard

Also the car is a original 5speed but the guy told me all he had was a auto harness so he put that in,after I put in a ka24de it started jus nothing worked tails lights,head lights,cluster etc....

Thanks!

[Infinitiguy19]

Check out the service manual for the plug information: http://www.nicoclub.com/FSM/