Both backup lights not working - problem solved.
Yesterday a neighbor told me that the backup lights on my '92 SSE */c weren't working. There were no other problems or symptoms, so I suspected that maybe both bulbs failed, but I was skeptical because the lamp monitor never chimed about it.
Investigation revealed that both bulbs were ok, the backup lamp/trunk release fuse was ok, but there was no voltage to the bulbs when the shifter was in reverse. If I moved the shifter a bit while in reverse, though, the backup lights turned on, so I then knew that the problem was in a switch somewhere.
I cracked open my handy-dandy OEM Pontiac shop manuals and found references to the 'backup safety switch' but there was no listing in the table of contents or the index! Thumbed through both manuals and found a section about the shifter, and that pointed me to the section about the 'transaxle position switch' but again, there was no listing in the table of contents or the index! There was also information about adjusting the 'neutral safety switch', but again, you guessed it, it wasn't listed in the index!
Because I had seen the info about the neutral safety switch, I opened the hood and quickly found the switch and attempted to loosen the mounting bolts and then discovered that both bolts were already loose. I moved the switch a little while the shifter was in reverse (with the engine off and the parking brake set of course) and the backup lights turned on. I tightened both bolts, and the problem appears to have been solved.
Are the 2 mounting bolts supposed to have lock washers on them?
If and when I ever need to replace that switch, what is it called? It seems to me that it may be called the 'transaxle position switch', the backup safety switch', the 'neutral safety switch', or the 'PRNDL' switch, and just for kicks I called 3 local auto parts stores, and none of them had ever heard of any of these parts! It'* a good thing that I didn't need to buy one today...
Lastly, how difficult is it to replace the switch? It looks like the cable is removed by removing the large nut on the metal arm on the switch rather than disconnecting the cable linkage, and there'* some kind of rubberized goop all over the electrical connector, so I can't even see the connector itself.
'99 Bonneville SLE, white, 112,000 miles
'02 Park Avenue Ultra, white diamond pearl, 88,000 miles