Wiring harness swap - identifying a few transfer case wires?

[Jbrownjr]

First post here.

1986 B2 2.9L 4x4 Manual.
Been working on this beast with my son for more than a year. We bought it as a project (not running) and replaced most of the charging system (relays, Distributor assembly, TFI, ECM...)
About a month ago we picked it up from a reluctant mechanic who had it running, but really rough. He found we had replaced every part he diagnosed that might be the problem, and recommended a new wiring harness. We found a donor 1986 B2 2.9L 4x4 Automatic. Not running just yet, but I'll save that for another thread. Simple request here is help identifying how the transfer case wires can be modified to work.

"New" wiring harness (from an automatic):
Round connector
Purple/yellow (Electric Shift Control Module to Transfer Case Magnetic Clutch Coil)
Red/Light Blue (From Neutral Safety Switch to Starting System)
Red/White (Neutral Safety Switch to Electric Shift Control Module)
Black/Purple (?)
Yellow/red (?)

Two-wire connector
Red (?)
Tan/yellow (?)


Original wiring harness (current manual):
two-wire connector #1
Yellow/brown (?)
Black/White (?)

Two-wire connector #2
Purple/yellow (?)
Black/white (?)

Since it's not driving yet, this maybe premature; but I've read elsewhere this donor wiring harness should work. I just can't make heads/tails of how to splice the new wires into the old connectors for the transfer case.

 

[Tiha]

"New" wiring harness (from an automatic):
Round connector
Purple/yellow (Electric Shift Control Module to Transfer Case Magnetic Clutch Coil)
Red/Light Blue (From Neutral Safety Switch to Starting System)
Red/White (Neutral Safety Switch to Electric Shift Control Module)
Black/Purple (?)
Yellow/red (?)

Two-wire connector
Red (?)
Tan/yellow (?)


Original wiring harness (current manual):
two-wire connector #1
Yellow/brown (?)
Black/White (?)

Two-wire connector #2
Purple/yellow (?)
Black/white (?)

Haven't had my coffee yet, but just a quick glance at the attached diagrams.

Two wire automatic connector,
Red From ECM to convertor clutch solenoid
Tan/Yellow +12v.
Souinds like you can ignore this plug.


Two wire Manual connector #2
Purple/yellow To back up switch
Black/white to back up lights

If your reverse lights work you can ignore this plug.

Do you read it that way? The colors are not a perfect match, but logic says that is what they are for. So maybe that helps a couple more.

 

[Tiha]

Could connector #1 from manual harness be
yellow/red instead of Tan/red?
that would make that plug for the knock sensor.

 

[Jbrownjr]

Been a while, but I have new info:

• Two wire Manual connector #2 (Purple/yellow To back up switch / Black/white to back up lights)
  • Yep! Original connector fits on the backup switch. No, backup lights don't work...and I found similarly colored wires in the donor harness (part of the "round connector") Sweet! I'll splice the original connector in later.
• The plot thickens on the other. The two-pin connector (two green wires attached to the transfer case, and Yellow/brown / Black/White into the wiring harness) I traced on the old harness. First picture is the original two-pin connector. One end is at this unidentified connector which sits on the engine side of the firewall, on it's way into the driver side cabin. The other end seems to be at Pin 30 on the ECU. Unfortunately the wiring schematics I've found have a different color wire there, and the routing doesn't end up at the transmission. I'm assuming it has something to do with shifting. Maybe neutral detection?