1999 9-5 wagon with 2.3 L engine. Neutral safety switch. Intermittent problem with reverse lights not working. Always started fine, so neutral signal was working OK. Indy still diagnosed problem as defective neutral safety switch, reasoning that the reverse circuit was not being completed.
But being a true cheapskate, I went to look further. Somebody had a nice write-up about taking it off and cleaning, so I gave it a try. A bit of a tug to pull out of the transmission, but not real bad. (Access this pup is below the battery tray.) Turned out the cover for this switch was held in place with small screws and it came off easy. Cleaned and repacked with dielectric silicone. Ohm meter showed all contacts working and still had problem with reverse lights. Now the plot thickens. Discovered that there is a relay for reverse lights under the dash and a quick slap made the lights come back on. Swapped with the fog light relay that I am not using and all fixed. The $12 relay solved the problem and the $280 neutral switch was not the culprit after all.
If my memory serves (which is known to be fuzzy), it seems that with the relay working, the gear position indicator on the instrument panel registers as it should. I think it was showing a bit off the marks between neutral and reverse. Could this be because the computer saw a good signal from the neutral switch and an incomplete in the reverse lights? Very possible!