Cruise -- If you don't have cruise it is not a simple "add-Parts" to make it work. I know of one person that installed the cruise steering wheel to try and make his work. He had to have his ECM reprogrammed at a dealer to match a similar Cobalt that came with cruise (dealer used the VIN number of a Cobalt that matched everything his Cobalt had plus cruise). Even after this his cruise light didn't work.
If you're going to change parts like turn signal switches I recommend you get a factory manual ($150 though) to make it easier. I haven't had the "pleasure" of replacing one.
I had the dealer add an aftermarket cruise to my car when I bought it. It's just a little pod on the steering wheel and really unobtrusive. The DIC just flashes "cruise engaged" once when it's on. Came with a 3-year warranty too. But I understand wanting to keep the stock look...
Posted how I did it in the audio/video post on my '07 coupe (manual trans). Repeated below.
For those of you who don't have factory cruise, this one is a no brainer to install. 1 hr to install (with lots of double checking voltages with a fluke - I'm a perfectionist). Bought mine on Ebay for $80 bucks (including shipping). Had the dealer reprogram the BCM for $75.
Installation instructions (supplement to those provided with the kit):
1.) Pull the fuse cover off the passenger side of the center console. Pull the cup holder out of the center console by pulling the front part of it toward you and lifting it out. This is where you put the cruise radio receiver after you hook up the wires (below)
2.) Hook the Red and Blue wire together on the supplied harness. Tie them to a single igniton source. I used a simple pair of 18-22 gauge splices I bought at Advance Auto Parts for $1.98. One to splice to the blue wire to the red wire. One more to splice the red wire to the ignition source. The ignition source I used was one of the two pink wires coming out of the big C3 connector in the middle of the Body Control Module = BCM (fuse block). They come out of position D7 in the C3 connector. On a 2007 (and I'd bet all others) this is on the top row, slot 7. From left to right--slot 1=Red/Black [batt + voltage], there is no slot 2 [slot 1 is twice the normal size], slot 3= not used, slot 4= Red/White [batt + voltage], slot 5=D-Green [retained accessory power fuse supply voltage], slot 6=thick pink wire [ignition 1 voltage], slot 7=two thin pink wires [ignition 1 voltage])
3.) Hook the black ground wire from the harness to a bolt that attaches to bare metal inside the center console between the seats. Look around, one isn't too hard to find. I used one that bolts down the BCM on the left (looking straight at it).
4.) Hook the grey wire from the harness up per the instructions with the kit (location 61 of the C2 connector -- next to the white/black wire going into location 62). If the wire doesn't have the 0.64mm microconnector on it (mine didn't), get one from the dealer. GM part #15359541 (dealer charged me $0.75). They'll even crimp it for you if you ask. I fudged it with a pair of needlenose pliers. Just do it clean so it isn't much bigger than the end of the microconnector (it has to fit into the C2 plug).
5.)Thread the supplied wire harness inside the center console from the fuse block to the cupholder hole. Hook the wire harness to the supplied radio receiver. Secure it to the center console inside the hole where the cupholder goes. I used velcro strips with adhesive ($2.98 at Wal Mart). Put the cupholder back in.
6.) Mount the supplied push buttons to the steering wheel after you put the battery in.
7.) Go to the dealer, fork over $70-$80 for 10 minutes worth of labor and have them reprogram the Body Control Module (BCM) to tell it the cruise control is there.
You're done. Cruise works just like the factory cruise (indication through the instrument cluster). The dealer tech looked dumbfounded when it worked. $160 bucks invested.