But wait; more box truck saga

[Toolmaker51]

Truck was vandalized somewhat, they tore up the lift-gate switches, for that modicum of scrap value in the copper. Won't belabor the point, but replacement loom was pricey and ridiculous procedure to acquire correct replacement. Major companies should screen and monitor distributors carefully.
First switches I got unsuitable for exposure to weather, there are boots made for those combined plunger and thread size, but couldn't meet affordable minimum order. Of course, matching of items in stock has become a thing of the past.

Pic is result of planning around of switches were 100% suitable, in material anticipated to get desired completion. Inset is the prior condition, with new loom in place, mainly for testing remainder of system, after cutting away the surplus housing. Just prior to the attachment of new, all old metal was sliced off and angle ground smooth. The smaller vertical tube, 1" square 1/8" wall, is original surface conduit to protect wiring.

The new housing is 2" square tube of about .093 wall. 4 holes face rearward of 5/8" diameter for switch mount, the body is substantially larger. It's longer than 2", but that helped fishing each out of it's respective hole, as each plunger entered. A scriber point was only tool needed to 'steer' them. After tightening retaining nut, installed weatherproof boot. Each is a momentary push button, very sturdy and positive.
Top of the housing is angled a few degrees to shed water, TIG'ed in place. Lower forward corner covers opening in top of 1" square tube. Two shoulder screws fasten housing to frame of lift-gate, not welded as original (or work done by previous owner/s). That allows and simplifies work or modifications later. Sealing top of the tube instead of a plastic cap was for an "in case of" situation, not being able to fish four switches attached to the loom. I had a strip of 2" to make a 'door' in back, and attach with small self tapping screws, with the roof and a bridge at lower end to withstand clamping in mill vise.

Functions are from the bottom, 1) energizes circuit, 2) lowers platform, 4) raises platform. Switch 3) folds platform when used with the *4, unfolds used with *2.

I'd appreciate assistance selecting components to build a latching relay for 1) to not make it a two handed affair. Electricity I can reasonably kluge. Electronics is not my forte'. Found all kinds of info on the DIY process but little [none] about 12 volts running equivalent of a Delco starter motor, there is some amperage, especially to tap the 3500 pound capacity. The truck wiring has a thermo breaker for overload/ short circuit conditions.