Check the listing for details. MILITARY TRUCK M939 PLUG &PLAY KEYED IGNITION STARTER SWITCH M923A2 M931 5 TON. Condition: New. Listed at 79.99 USD. You are viewing a keyed ignition switch for the M900 5-ton truck series. - Work's with the M939, M939A1 and the M939A2 trucks. - Comes With Two Key's! -The only modification you have to do is drill out the mounting hole a bit larger! This switch will plug into the trucks wire harness where the original switch unplugs from. It is very easy to install and makes the truck much more secure. You will need a test light or multimeter, adjustable wrench, drill with Step Bit and a flat head screwdriver for the install. The switch pictured is the style you will receive! I have installed Dozen's of these switches with great success!!!!!! Free Shipping Anywhere In The USA Please Check Out My Other Items!!! On Sep-23-16 at 11:14:40 PDT, seller added the following information: Add a map to your own listings. FREE Trial !