Diff Lock Light Wiring for 83-89 -- Modern T Case Switch Answered
To wire a newer style Diff Lock Warning Switch to an older truck
The 83-86 Defender
Black w blue trace goes back into the instrument cluster.
Green w yellow trace
Green with brown trace
Connect the green w brown trace to the existing Blue w black trace wire. This will lead back into the cluster.
Add a ring terminal to the green w yellow trace wire and ground to any screw on the transfer case.
Your diff lock light should now work.
a year from now when I need this now I know where to look for it.