help need 5th gear switch function description

[kzbill]

Does anyone know the TRUE FUNCTION of the 5th gear swith, AKA: nuetral saftey switch, AKA: PNP switch, AKA; transmission position sensor located on the bottom side of the trans????

91L efi 5spd

[festivaWES]

From my understanding its not for shifting gear of anthing to that nature, but a saftey feature to where you can't start the motor while it's in gear without depressing the clutch. s-10's don't have them...you are able to start the truck in first without having the clutch engaged.

[kzbill]

My understanding is it may have something to do with signaling the computer? I have to do a continuity check on it later.

[kzbill]

I did the continuity check and a bunch of reading, this seems like it is ignored in the manuals. I read on here last night that it may be a signal for the computer to turn on the EGR so I got the switch connection fixed and all seems well.
preliminary test of about 50 mi. with no code!! Yippeeee!

[kzbill]

Still can find no good description of the function of this switch? says nuetral safety in the book but I have heard other things too

[DuritzCrows17]

If it helps out I have mine disconected on my swap and my car is running, I do have the idiot light on (low oil pressure) but besides that the tranny and the rest of the engine is performing cherry.

[roycehof]

Don't quote me on this but I believe that when it in gear it sends a signal to the computer. Somehow that input is used for determining the the right signals for the rest of the engine management system. I notice that my idle moves slightly with my clutch pushed in when I place it in gear and I think it has to do with that switch.

[kzbill]

Thanks I'll try that too

[Deathshead]

just ground it.. mine runs great without it.

[kzbill]

I installed the new optical sensor now all my ignition problems seem solved even the low speed miss or "pop"
I also had an issue with the Idle air control motor, that was the bogging and stalling.

[FestYboy]

I did the continuity check and a bunch of reading, this seems like it is ignored in the manuals. I read on here last night that it may be a signal for the computer to turn on the EGR so I got the switch connection fixed and all seems well.
preliminary test of about 50 mi. with no code!! Yippeeee!

the EGR trigger for the PCM is correct, the nutral safety switch is only on autos and there's a clutch position switch that is used on the manuals to inturupt the starter signal from the ign switch, but that's located right above the clutch pedal.

[kzbill]

Thank you