GM Neutral Switch Solutions

I'd like to discuss this matter in general terms but the specifics of my application are as follows:

The vehicle wiring information I have found on this site was mostly correct for my specific vehicle, but I noticed at the end that I had not connected up the neutral safety wire. Noticing that there was no listing for a neutral safety switch, I had a hunch that was verified by re-reading the alarm's installation manual: There is no direct connection to an electrical neutral safety switch. The book says that many GM Trucks and Dodge Dakotas accomplish this with a mechanical interlock. The fix described in the manual is to tap into another, somewhat related interlock, one that prohibits the key from being removed unless the shift lever is in park. The alarm's nss shutdown input (-) is to be connected to the key cylinder's green wire (+ side) and then the remote start module's purple start output wire is to be used to pull a relay to ground, in parallel with the door switch on the tan wire (- neg. side of key cylinder).

Why is this purple wire used? Can I use the ground provided already through the door switch.

....Ok now that I figured it out, I decided this information might be useful to someone else, so I'll post it anyway.

Answer: Without the relay, everything would work fine...until you tried to get into the car, opening the door would kill the remote start.

A couple more questions related to the matter:

Is there a way to avoid the 'side affect' of not being able to insert the key while the door is open?

(I'm thinking about using a 555 timer to turn a relay into a time delay dropout relay, maintaining the circuit across the key-switch during a remote start event. Let me know if you're interested.)

Will this alternate set-up allow the remote start to be used like a turbo timer? (no I'm not going to put a turbo on the s10)

Concerning the additional requirement to tie the brake shutdown input (+) to the yellow, ignition input to the alarm. Why?   

(The installation manual says to prevent the remote start from activating if the key is left in the run position... I'm hoping someone can expand on that and help me 'get it')

0 and 25 and no responces. uh oh. Ok here's what I have come up with so far:

I was wrong about a couple of assumptions previously. The electrical signal being tied into is the 'key in the ignition, and the door is open (annoying)' buzzer circuit. The thought being that if your key is in the ignition and the door is open, you have an electrical signal that says that you may possibly not be in Park. It's broad and covers more scenarios than just being in park. I see that getting me into a little remote start trouble.

Another wrong assumption is the reasoning for the remote-start-output-driven relay in parallel with the door switch. It is the to prevent scenarios where there is a key in the ign with the door closed and a remote start is intiated. The wire being tapped to the green wire is not intended to be the nss wire (It shows the grey wire on the (+) side of the key cylinder, but I had thought that was an error.

The circuit goes: +12V-buzzer->^(-)alarm shutdown input(parallel)->key cylendar-door switch^in parallel with relay to ground driven by remote start output->ground.

The case (turbo timer) where the remote start is initiated prior to pulling the key out, so that the vehicle remains running doesnt seem possible without modification, as is the side affect of not being able to put the key in without first closing the door.

The key switch, when in run opens in the buzzer cicuit which is why the need for the connection to the ignition input to the alarm {(+) brake shutdown}. this must also be temporarily opened by the same (DPDT) or additional, similarly timed relay.

The solution I have come up with for the remote initiated prior to pulling the key out. requires an ignition input and a remote start input to energize a relay opening a contact in series between the grey, shutdown wire's connection and it's connnection to the existing door buzzer circuit, for a short time. The solution that I see working for the door side affect is a relay who's NC contact is in series between the grey, shutdown wire's connection and the door switch. In the case of the door-open-induced shutdown; as long as the relay is timed (RC delay) so that a remote start is initiated by first knowing that the key is not in the circuit, the same circuit can be forced open by a relay, subsequently, without reason for concern for safety. This allows the key to then be inserted with the door open not causing a shutdown.

I guess this closes the topic, unless (please) someone has another, more simple way to accomplish this. I will post a schematic for this soon.

The GM vehicles they are refering to that have a mechanical neutral safety wire tend to be the ones with a purple starter wire at the ignition switch. There may be some out there with a yellow starter wire, but I haven't seen one, and I have been installing remote starters for quite a while. By the mid nineties, GM had switched to a different system. Your s-10 will be just fine.

Big props for trying to be as safe as possible, tho.