The pin # orientation should be on the connector case.
Looking at the CD , this connector [49/2] is located just above and to the right of the pedal, right of the steering coloum.
If you can not find pin #'s, use the below info to locate what you need...........

Pins 1 & 2 are Gry/Yl-Blk/Rd..
this will be back up switching.
2&4 will be V/Wt-V/Gn..this is starter lock-out.
These 4 will be the wire color codes for the proper 4 prong connector.
Continuity at the connector , on the side that goes through the floor to tranny for 1 & 2 should be found when shifter is in R..
...or, jumper 1-2 at the other half of connector [ live side ] and BU should come on..if not . problem is NOT in the switch part of circuit, as you are simply eliminating that funtion w/jumper...
Don't forget to have key ON when testing the live [lamp] side