I made this diagram for Clyde65, but thought others might be able to use it. This is just a schematic drawn to hopefully be a little clearer than the factory service manual. This is how to hook up a factory cruise control module for cable throttle body's. It's really fairly simple, you just need to make sure you get the right module. I personally used one from an Astro van, but mid 90's and up S-10's use the same module. The one you want will NOT have a wire in the "H" terminal of the module plug (see 2nd pic, notice the missing wire in the middle). Once you have that you'll need a 4 prong brake light switch, it will have 2 normally open and 2 normally closed terminals. These can be found in alot of 70's and up GM cars and trucks.
To run the factory cruise you need a 4000 pulse per mile signal. This comes straight out of the PCM, it's the signal to the speedo, radio ect. On a '99 to '02 truck, and F bodies it's the C2 connector (the red one) pin 50 dark green/white. The one at C2 49 is a 128k ppm and is only used for ABS, Don't try to use it.
You'll need a 4 wire cruise control switch to turn it on and off. If you have a '83 or newer column and it has cruise on it, it should be a 4 wire. For older columns that use a single screw to hold the turn signal lever the '81-'82 trucks and vans have a lever that can be converted that will work. I posted a "how to" here.
http://67-72chevytrucks.com/vboard/s...=cruise+switch
Other than that it's a matter of hooking up the cable to the TB and mounting the module.
This will work on almost any EFI engine that has a 4k PPM speed signal so if you have a TPI, LT1, or LS, all GM's use that signal.
I have this same set up on my own car and have about $50 max in the whole thing, and it works way better than the aftermarket cruise I have on another car. this cruise works flawlessly! set it and it stays there and doesn't fluxuate like the aftermarket.