5th Gear Switch

[bolokid]

So I am trying to get my recently acquired 93 Festiva ready for Westiva and then the trip to Madness in the fall. I changed the crank seal, cam seal and timing belt. As I was putting a new alternator belt on Saturday I notice a wire (2 green wires) wrapped around the back of the alternator harness. I followed the wires down to the right hand side of the transmission. The shop manual refers to this as the 5th gear switch but cannot find any more information on it.

What does this switch do and where does it plug into?

Thanks.

[fastivaca]

Fifth gear switch is just below the passenger side axle.



The wires have broken off on this transmission which is probably what has happened on your car.

[bhazard]

What's it for?

[bolokid]

Fifth gear switch is just below the passenger side axle.



The wires have broken off on this transmission which is probably what has happened on your car.

That's the one. The wire is still on it and is probably 2 feet long. The plug on the end of it is wrapped around the alternator wiring.

Any idea where it plugs into? Movin gave me a suggestion, tomorrow I will try to search it out some more.

[fastivaca]

What's it for?

That is a very good question! Couldn't find any reference to it in the EVTM and nothing much is said about it in the FSM. Haynes doesn't even mention it.

That's the one. The wire is still on it and is probably 2 feet long. The plug on the end of it is wrapped around the alternator wiring.

Any idea where it plugs into? Movin gave me a suggestion, tomorrow I will try to search it out some more.

You should find the plug down around the starter, down between the transmission and the firewall... at least that's where it is on my car.

Ian

[monkeykiller1996]

maybe it has something to do with the lockout thing with the tranny (bacally it wont let you shift from fifth to reverse it locks reverse if you try to shift from fifth to rev.

[tooldude]

I don't have a 5-speed here to look at. Are there only 2 external switches on the trans case? The neutral gear switch and the clutch engage switch are wired in parallel for every year. Their basic purpose is to indicate engine load and affect related factors such as injector on-time (or FBCA on the carby). I didn't find much on that.

[bravekozak]

That's a simple one. On Festivas that have the shift light, it is a simple way to tell the ECA when you are in the highest gear. When you shift into the highest gear, the rail pushes the ball in to complete the circuit on that switch. The computer knows not to light the shift light because there is no "next gear".
It's called the fourth gear switch. I searched for "shift light" and found a couple of threads that explain it. Here's one.

[fastivaca]

I don't have a 5-speed here to look at. Are there only 2 external switches on the trans case? The neutral gear switch and the clutch engage switch are wired in parallel for every year. Their basic purpose is to indicate engine load and affect related factors such as injector on-time (or FBCA on the carby). I didn't find much on that.

There are two sensors/switches on a stock manual Festiva transmission. One is the 'back up lamp switch' and the other is the 'fifth gear switch' as named in the 92 Festiva factory service manual.

That's a simple one. On Festivas that have the shift light, it is a simple way to tell the ECA when you are in the highest gear. When you shift into the highest gear, the rail pushes the ball in to complete the circuit on that switch. The computer knows not to light the shift light because there is no "next gear".

I've not seen a 90's Festiva with a shift light. Would really like to know what this switch does as I discovered mine has been disconnected for some time. I reconnected the wires and will see if there's a noticeable difference. The one I photographed is one of my spare transmissions that will need to have the switch replaced.

Ian

[bolokid]

I reconnected the wires and will see if there's a noticeable difference. The one I photographed is one of my spare transmissions that will need to have the switch replaced.

Ian

One end attaches to the transmission, where does the other end plug into. I cannot seem to locate any loose plug laying around.

[fastivaca]

One end attaches to the transmission, where does the other end plug into. I cannot seem to locate any loose plug laying around.

Here's a photo or two that I hope will help.

... and one from further away



The end of the zip tie is resting on the plug. It should come out of the harness in the same spot the wires for the starter do. From the sensor the wire comes under and behind the transmission but above the cross member and up to the plug in the harness.

[Damkid]

My guess would be that 5th gear switch would have originally been used on the 88-89's that did have a shift light

But then 90'+ they just ditched the shift light but left the sensor in place leaving it useless in the 90'+ models

[F3BZ]

this is a great question and a real enigma. all the shop manuals show a 5th gear sw. but don't say what it does. none of the EVTMs show what it does. carb or EFI. the 88 MTX training manual doesn't. there is a 4th gear sw mentioned for the early 4spd trannys. i don't think it's for reverse lockout because best i can tell that is a purely mechanical failsafe. there is no 5th gear or OD indicator light to power. my guess was that it sent a signal to the ECA but there isn't any mention of it in the engine/emissions diagnosis manual either. last resort was to pull out 93 wiring diagrams. no 5th gear sw shown on those either. i even tried to pick out anything showing a green/green w black stripe. nada. the 4th gear sw was used in the carbbed L to send an input signal to the EC and along with manifold vacuum and RPM inputs decided when to illuminate the shift indicator light. so i think damkid may be right. but why not just put a threaded plug instead of a costlier sw to nowhere?

[bolokid]

Here's a photo or two that I hope will help.

... and one from further away



The end of the zip tie is resting on the plug. It should come out of the harness in the same spot the wires for the starter do. From the sensor the wire comes under and behind the transmission but above the cross member and up to the plug in the harness.

I found it and plugged it in. I am also in the process of exchanging the speedo for a tach/speedo instrument cluster so cannot tell if any other lights are on. I should be test driving tomorrow to see if there is any difference.

Thanks to all for the input. Ian, I am now one step closer to making the trip to Westiva in this one.