This is a Classic Weaponlight 960, right? When you say you removed the body adapter, do you mean the part that the tailcap screws onto when it uses 3 batteries? In the chart below, it's the A21 adapter, which screws onto the L90 housing. Is that how your 960 is? If so, the problem is likely at your tailcap-to-body connection, as the shortened threads of the L90 housing aren't meant to take a tailcap and probably do not reach the electrical contact in the tailcap to make a complete circuit. Compare the length of the threads of the adapter and the body housing, the threads on the adapter should be longer.



To be certain, take your complete body housing/lamp/bezel, place two batteries in it, and then take a piece of metal (nail, paperclip, butterknife, etc) and touch both the battery contact and the wall of the flashlight - you're completing the circuit without a switch. If it lights up, you now know that the problem is the switch/body connection. Unfortunately, there is no easy solution, as those shortened housing threads are not meant to take a tailcap, even though it may seem like it fits. You'd need to remove metal from the tailcap or the body housing (which isn't guaranteed to work), or replace your L90 body housing with the L60 housing (to use with your A21), or replace the body housing with a normal two-cell flashlight body.