100 series going into 4x4 by itself

[Rex210]

My 100 series goes into 4 wheel drive by itself at times, I have to reverse it to unlock as the button doesn't work but I can hear the clicking of it engaging/disengaging, when it comes out 4 wheel drive the button works as it should, any help would be appreciated as mechanics tell me to go to an auto electrician, and the auto electrician tell me to go to a mechanic, it has done about 225 kilometres

 

[GeekOKent]

What specific 100 series is it ? I thought they were all either permanent 4x4 or had manual hubs that needed locking by hand from the outside ?

 

[Shayne]

Inexperienced assumption the centre diff means 4x4 or not perhaps ?

 

[GeekOKent]

A picture of the button would help

 

[karl2000]

Sounds like centre difflock switch or wiring - what has your auto electrician done before sending you to a mechanic?