Neutral Safety Switch

[suprashy]

Hi folks! I have an 87 Auto Turbo. Reverse lights haven't worked for years, and I finally have decided to see what's causing the problem. No tranny swap was done, and from searching this forum, a visual inspection shows all connectors are connected.

Bulbs are good, and the 7.5 gauge fuse which powers other items (in addition to the reverse lights), are working fine, so I assume the fuse is good.

I was about to start diagnosing (and learn how to using the TEWD and TSRM electrical schematics) the electrical wiring/connectors involved, but then I thought of something which yielded the following:

Car starts in P, R, N and D and continues to run like a champ as it always has.

If I understand correctly, the Neutral Safety Switch (NSS) prevents a car from starting in other than P or N. A bad NSS would prevent a car from starting. But it appears I have the opposite issue. The car starts in any of the gears described above. Can this also be a result of a malfunctioning NSS? And if I understand correctly the reverse lights are also wired into the NSS?

The TEWD shows a "backup light switch", which I'm thinking is the NSS for an auto. Meaning the Auto has one switch that's the NSS which also incorporates the reverse light mechanism.

I'm thinking I have a bad NSS which is causing the car to start in any gear, and is also preventing the rev. lights from coming on.

What do you think?

Tks!

 

[hvyman]

Switch prolly failed in the N or P position allowing you to start when ever. Back up lights is the reverse lights which is a totally different system that just shares the same power source and fuse.

 

[bioskyline]

i may be wrong, but i think the neutral start and reverse are connected to electrical box on the side of the tranny with the shift linkage, and when the shifter is in R its supose to turn the lights on when it engages the reverese gear.

atleast thats how i got my rev lights and NSS to work when i did a 5 spd swap, was wire them into the AT wire harness (i just cut it off the trans)

 

[te72]

Hmm, my reverse lights don't work, and I merely put a wire in the one end of the NSS on my car to bypass that. Wonder if I need to find another way to get my reverse lights back, or if I have another issue?

 

[suprashy]

Switch prolly failed in the N or P position allowing you to start when ever. Back up lights is the reverse lights which is a totally different system that just shares the same power source and fuse.

Does that mean the autos have a backup light switch AND a NSS switch? I located the NSS switch on the passenger side of the tranny which goes to two large round connectors to the harness in the manifold area.