try Grainger locally. I had same brand switch for drive unit, they had it.
http://www.grainger.com/Grainger/searchresults.jsp?kindOfSearchRedirect=Regular&sea rch_type=brand&QueryString=CARLINGSWITCH&type=SWTR &action=Go!&isMatch=true&state=1
contact direct ( carlingswitch)
http://www.carlingtech.com/contact-us/index.asp