Cruise control on FC
 

I have a '91 RX-7 S5 and I was wondering if the ecu has for cruise control. It has all the cables for it under the cluster. Can I just plug and play or do I have to swap out the ecu?

Not a 2nd Gen owner, but I found this in the 2nd Gen. section using the term 'Cruise Control' in titles only....
https://www.rx7club.com/2nd-generati...nstall-797686/
Maybe a 2nd Gen owner can confirm, but like the 3rd Gen., I believe all the wiring is in place but I think the Turbo models were different than N/A cars, and you'll need to make sure your components come from a S5...S4 stuff isn't the same.

Yeah, I read that S4 and S5 aren't compatible and I read the article you posted. Thanks. It was very helpful. I just wanted to upgrade mine have most if not all the options.

All you need are the cruise control parts from the same series of RX-7:
https://www.aaroncake.net/RX-7/cruise.htm