Reversing light sensor

your speed sensor is always placed on the gear-box...u may have two or three looms going out of the-box, the other one is for your reverse lights (and oil if u have the third one)

it will be the revers switch that's connected to the gear box when you put the car van truck into reverse it hits a switch and turns reverse lights on might just be the wire has come off or the switch is broken

It's not that simple anymore . The transmission range sensor switch is what they have now . This range sensor informes the PCM - engine computer what gear the vehicle is in. When you put the gear selector into reverse B+ voltage from the range sensor to the PCM tells the PCM reverse has been selected , the PCM then will energize the reverse lamp relay (located in the under hood fuse/relay box) there by turning on the reverse lamps . There are two fuse's in the under hood fuse/relay box . F27 10amp. & F35 10amp.

Sounds like a linkage adjustment problem

Try checking the bulbs..Or your netrual safety switch maybe out of align

sounds like your issue is either involving the torque convertor, or more than likely the transmission is at fault. your gear shift lever is actually mechanically linked to the trans, the gear position sensor would not cause the van not to move, sorry for the bad news!

With engine off and key on, emergency brake set, place the gear selector in reverse, using a volt ohm meter check for voltage at bulb terminals. If voltage is present then the switch is working and the wiring to the lamp is good. Next check the other terminal with the ohmmeter to ground for connection. Sounds like a bad ground.

gear box mount is worn out by the sounds of it , you can check this by puting a jack under gear box and jack it till the engine lifts about 4" then you can see if you can get a leaver in the engine mount, hope this helps

This may simply be a case that the gear linkage is twisted too far round to the right, so that when the lever is pushed as far to the right as it can be, its not actually pushing the gearbox over far enough.
Try slackening the clamp bolt(s) and twising the shaft 1-2mm in one direction (the direction that moving the lever to the left is) If its no different or worse, twist it 2-3mm in the opposite direction.

One of the most common causes of hard shift is the clutch no fully disengaging, also do you put it in 2nd before you try 1st or reverse, it helps stop gear motion in the trans which eases the effort to engage the non-synchro gears, which first and reverse are most likely.