
One of the modifications that I commonly make to my military vehicles is to add a keyed battery master disconnect switch. This adds a small amount of security even though the switches all use the same key and have simple warded locks, because the trucks normally don’t have any keyed locks or switches at all. The switch I usually use is Pollak part number 51-916, and I buy them from various distributors or on eBay. They are much better switches than the cheap plastic knock-offs of Hella switches or battery-mounted knife switches that are commonly found. There are also similar heavy-duty switches that other military vehicle collectors like to use, but I stick to this model so I only have one kind of key to keep on hand. I just finished installing one of these in my new M923, and here’s how I did it.








