Factory GM 60's Engage Switch w/ Rostra Cruise

I would like to figure out how to install one of those early, 60-70's single push button engagement switches with the 250-1223 Rostra cruise kit. I haven't looked at the schematic yet so instead of re-inventing the wheel has anyone did this? Anybody heard of it being done? I figure I would just always have the circuit powered, (Ignition), and either loose the resume function or install a push button switch elsewhere. I'm not sure if any of these functions are open or closed. But if I remember correctly the engagement switch option can be set to open or closed. I could also find a N.O or N.C. push button switch for the resume function. What do you think? Thanks! Larry

I've done some installations on both styles of cruise, 60's GM OEM units as well as those 70's style Dana/Sears/Rostra cruise kits. I've wondered the same thing. One thing I recall is the early GM unit is 3 wire, and the Rostra is 4 wire. Is that correct? If so, it may be that the 4th wire is just for the resume and the other 3 do the same thing? I only have Rostra kit here right now, I don't have a stock GM lever to test against the Rostra control. Have you gotten any further on this?

I did find this diagram of an early cruise system. It looks like the switch is N.C. on the Red and Brown/White wires and then all three are connected when the switch is engaged. It just needs to be determined if the Rostra can power up and engage with these functions. Along with a hidden resume switch it might work. It would be powered at all times when the ignition is on but that's no biggie; I never turn mine off. I don't have my system yet. Maybe you can see see if this will work by looking at your diagram. Actually, I should have the diagram stashed in my records from an earlier install I did a couple years ago. I'll look too.

Based on the Rostra function chart here's what I have come up with: The 60's control switch will be used as a SPST momentary switch to set the cruise. Since it looks like the BRN/WHT wire is always hot with the switch at rest or at "Set" it wouldn't be used. The control switch will be providing power continuously at the RED/GRN wire just as if it was left on. The ignition will power the rest of the system as designed. When the switch is pressed, power goes out from the WHT wire to the Rostra GRN wire. If a resume function is desired then a separate SPST momentary switch can be used. This switch is also powered by the RED wire and when depressed, sends power to the YEL wire. The Rostra DIP switch would be set to "Open Circuit" What do you think?

I'll have to dig out my kit with the diagram and see but it sure sounds like you have it figured out!