If its a warn, its probably not the actual solenoid contacts, but the control (switching) terminals of the solenoid slightly corroded and intermittantly powering the solenoids.
They are not connected well behind the plastic cover, using just sprung terminal connecters, where they should be eylets and nut and washer to secure.
I didnt trust mine, didnt like the size and couldnt be bothered cutting all the terminal connectors aoff and resoldering proper ones on so went for an Albright Solenoid pack.
1/4 the size, sealed and good connectors.
Fitted.....
http://www.jeepkonection.com.au/prod...olenoid&cat=51
Matt.