On my older wagons ('81, '82, '86) they're the same all around and from year to year. This makes manufacturing sense -- why design a different switch for the tailgate? That would make it a $100 part instead of a $35 part. :-)

Go to a boneyard and scavange a few door switches from the right rear doors of 240s. These are the least used.

Also, if you're careful, you can disassemble, clean, lube, and reassemble these switches to get many additional years from them. I've done dozens.

Be sure to clean the rust 'n corrosion away from the mounting screw and hole -- the screw makes the final ground connection.

Incidentally, these switches all have internal dual contacts (the extra is for the driver's door -- chime alarm, delayed light, etc.). You might try swapping the wire to the other tab on the tailgate switch.

Is the bulb good?
--
Don Foster (near Cape Cod, MA)