I've got a question on a 1990 Firebird Formula; if you wanted to bypass the Neutral Safety Switch, where would you do it? The switch on my car seems like it has been bypassed.
The reason I say that is because I changed out the switch and it still will allow the car to turn over in gears other than P or N.

Also, my 4-wire, hatch release switch won't work. It does work if you bypass the orange/white wire in the harness. Again, this is the NSS wire. I have examined the wires coming out of the harness at the gear shift and nothing seems to have been changed there.

So, where is another place where someone might bypass that switch? I suspect the original NSS was bad and instead of replacing it the PO had it bypassed somewhere. Thank you for your help!

 

The starter crank power comes from the ignition switch on a fat yellow wire. It goes to the VATS starter enable relay where it comes out on a fat tan/white wire leading to the NSS. It leaves the NSS on a fat purple wire and goes to the starter solenoid. Someone may have been having VATS trouble and may have wired the yellow wire straight to the purple wire which would bypass both the VATS and the NSS. Your best place to look would be under the dash and at the VATS relay, since you say it appears nothing has been modified at the wiring near the NSS.

 

That’s great! Thank you for the reply. The weather today is pretty awful so I will check that out as soon as the rain stops this weekend.

A quick way to test weather the VATS/NSS was bypassed that way would be to get a non-chip key made and see if it will allow the car to fire and start?

 

If it was bypassed the way I describe, with a non-chip key the car would allow the starter to crank, but the engine wouldn't start because VATS also kills the injector pulse.

Of course, what I described is only one possible reason for what your experiencing. I'm curious, if you try to start the car with the NSS unplugged does it still crank the starter? If yes, that's proof positive that it's been jumped out elsewhere. If not, perhaps both the old and the new NSS aren't adjusted properly? At any rate, if it does crank with the NSS unplugged I'd start by looking at the yellow wire coming from the ignition switch to see if any wires have been "backyard hack" tapped into it, and if so that'd be the wire to follow and eliminate to put the NSS back into the circuit.

 

You know, when I changed out the NSS for the new one, I didn't think to try to start the car with the switch disconnected completely. I will pull the center console and disconnect the wiring harness at the NSS and check for a start/no start condition and report back.

Thanks again for the help! It's really appreciated!

 

Cool, I'm happy to help, and yeah, knowing whether it'll start with the switch unplugged will be a major troubleshooting aid and will direct us to what should be looked at next

 

Hi OrangeBird, sorry for the slow reply. I was waiting to get some parts to fix my parking brake before I took the center console out so I could do that job AND check the NSS.

As suspected, I unplugged the harness connector from the NSS, put in the key, turned it and it cranked right over. Again, there are no wires out of place near the switch itself.

Is there something I should look for under the dash? Perhaps near the steering column?

Thanks!
David

 

Hi David, yes indeed you should take the plastic kick panel out from under the dash and have a look at the wire bundles in the area of the steering column, most specifically looking for that fat yellow wire that's likely to have been tapped into. If you can, a few in focus pics of the wiring near the column would possibly make finding this easier , you know, the ol "a picture is worth 1000 words" thing and all

 

Orangebird,

My apologies for the very slow reply. The weather turned quick last Fall.

Here are some photos. Let me know if you need better ones or close ups of something.

Thanks!!

 

Hi Dave, those crimp connectors (Butt connectors) are not factory and right there is the cause of your neutral safety switch being inoperative. My best advice would be to document what it's wired like now, put the wiring back to it's factory configuration, and I'll bet the NSS begins functioning again. Just curious, does/did this car have a remote starter installed? That's the usual reason for those wires to be altered, either that or perhaps an alarm system (tapping a relay into those wires to allow the alarm to disable the starter if it's tampered with)....

 

Ahhh, okay, it looks like the connectors are connecting red to yellow and splicing into the white wire. When I got the car it did not have a remote start or alarm installed. However, that doesn't mean it wasn't removed before I got it and the wiring was left.

The other possibility is this was done to fix a non functioning NSS perhaps?

I'll see what I can do about taking it back to stock. Thanks!

 

Should there be no splices in a factory set up? I'm reading the schematic but I'll be honest, I'm weak on understanding wiring diagrams well.

 

Hi Dave, yes in an untouched car none of those wires would have splices in them, and yes I'll bet they are part of someone's quick fix for a bad NSS. I'm sorry I don't have any pics of that area's wires showing what they look like, if you do a search on places like EBay you should be able to find a factory service manual (from GM, not the "Haynes" type) that will have clear schematics with pics of the wiring.

 

Orangebird,

Ok, got ya! Time to break out this guy and the coffee!





Thanks for all the help!! I’ll report back after doing the work and seeing what happens.

 

Great, once you've gotten rid of whatever non factory wiring there is involving those crimp connected wires, let me know how it turns out