My car came with a 'custom' toggle switch for the convertible top-hacked up junk IMO. It has12v power in and then two positions for up and down going out to the hydraulic pump. My newly obtained period correct convertible switch is ready to go in. But I am not sure what the 4th connection on that switch is for. I'm guessing a ground but before I ruin the switch can someone confirm?

 

Don't guess, use the wiring diagram in the Chassis Service Manual, and an Ohms meter as required on the switch.


i am more familiar with the '68-9 three wire switch.

here's a wiring diagram, maybe it has the top switch shown

https://classicoldsmobile.com/forums...ease-help.html


this shows a 3 wire switch
http://www.flickr.com/photos/robsalb...7602930020786/

sounds like you need the wiring bit and switch connector block too.

 

Actually, I think the convertible top wiring diagram is in the Fisher Body Manual.