elextronic diff lock not woking

[mrw]

I have a Tn75SA and the elextronic diff lock is not working. I do not know how the system works in order to try ad diagnose the propblem. Is the diff lock operated by a solonoid that is operated by the switch on the fender? If so where can the solonoid be found and does anyone have a part number for it?

 

[mrw]

Anyone with any knowledge of how the electronic differential lock works? With all this snow I would like to get it working again.

 

[Jbrink64]

I'm pretty sure it is operated via the rocker switch, then the FWD module, which controls the diff lock solenoid.

 

[RickB]

The solenoid is located in the services control valve, tucked between the fuel tank and rear axle center section housing.