Technical Transmission sensor question

[smahaley]

Hi all - so... this is from my 1978 Spider; 5 speed manual originally delivered to California. I'm in the process of restoring / resurrecting this car. I have the Haynes and the Pininfarina manuals and neither shows the top sensor. I experienced an unscheduled exploration of the trans and found that there are - unique I think to the California models - more dowels in this transmission than usual - and the final dowel is there to actuate the switch on top of the trans.

The lower sensor I believe is for the reverse lights.

Question: Anybody know what it is for? and ... Do I need it?

Thanks in advance!

 

[bugsymike]

Not much help and I agree about the reverse switch on yours, but on the older four speeds they didn't have that switch above the oil level plug and of you follow along on the same plane to the rear where the plastic wrapping is and there is what looks like a bolt with plastic on it which is where I have seen reverse light switches.
Apart from that, can you get a serial number from the top switch to identify it. My only guess would be a starter inhibitor switch, but I have never seen seen one on one before.

 

[Slotman]

So it's not shown on a 78 wiring diagram? Just curious if it showed a wire color, or description of what it is? But bet you already checked that!

 

[124BC1]

Sender on side of trans. is operated by engaging 3rd or 4th gear and operates a solenoid on the carb which prevents the throttle closing fully on the overrun. (so, reduces exhaust emissions when throttle is closed).
I agree with @bugsymike - reverse/back-up lights switch is on the rear trans. casing
and the mystery Sender/switch on top of trans. is probably a starter-inhibitor switch.

 

[smahaley]

Sender on side of trans. is operated by engaging 3rd or 4th gear and operates a solenoid on the carb which prevents the throttle closing fully on the overrun. (so, reduces exhaust emissions when throttle is closed).
I agree with @bugsymike - reverse/back-up lights switch is on the rear trans. casing
and the mystery Sender/switch on top of trans. is probably a starter-inhibitor switch.

Well there it is…. Just now getting around to this …