On my 1990 4x4 Auto 4runner the 4x4 doesn't engage. I am seeing a wire connector broken and attached to nothing. It is two green wires with yellow stripes on each. They come out of what looks like a sending unit on the transfer case actuator motor. I have zero idea where these wires go to and I am assuming that this is at least part of the 4x4 inop problem. Any ideas? or any others out there can look under their trucks to see where these wires go?

 

There is no transfer case actuator motor. The Green-Yellow and Purple-Yellow wires going to the ADD front differential are to operate the 4x4 light in the combination meter when the ADD engages. They have nothing to do with whether it engages, they only indicate once it has engaged.

The ADD is engaged/disengaged via the two vacuum lines going to the ADD. Those in turn go to the VSVs on the right apron, which are operated by the detection switch on the transfer case.

Good luck!

 

Ahh, ok thank you so much! I would still like to connect these wires. At least now I know about where to start to trace them back. So the 4x4 is 100% vacuum operated save for the lever in the cab?

 

The ADD is vacuum actuated. H4 in the transfer case is lever operated. If you have the A340H transmission, L4 is actually a small automatic transmission, which is actuated by fluid pressure.