I've just been through this with a Gen IV. Unfortunately, the Gen IV cruise control goes through the body control module (BCM) and is not as easy to hook up cruise control. I ended up buying the module from Speartech, as that was the only one I could find.I'd like to tap into the knowledge base here if I could, with a little bit different project.
I have a JK build that I'm ripping all the factory wiring out of. In it's place will be a new (simple) chassis harness from Painless. Wheel speed sensors, ABS, Jeep ECU, TIPM, dash, cluster, column, all going away.
Going in is a LS3 crate/6l90/Hero3spd w/vss tail. ECU is a E38. Obviously, the drivetrain will be stand alone.
I have a few questions:
*If I want cruise control, is there anything else I need? As I understand it, GM has cruise tied into the brakes and speedo some how. This is driving my confusion.
*Tap shift. That's just between the E38 and TCM correct? I'd just need a switch to send the tu/td signal?
* Stand Alone harness. I see a dizzying amount of harnesses out there and know nothing about the companies. Hell, even Painless makes a harness, and a chassis/engine combo, but I don't see the 6l80/90 as an option.
Can you guys recommend a harness brand? Any members on Pirate making harnesses that would fit my needs?
I actually went with speartech for everything. Expensive, but one stop shopping. My only issue is there was not a starter wiring circuit in the harness, so we had to build that separately. Not sure why this is, but it wasn't on the wiring diagram so I assume it wasn't a mistake. Not a lot of extra work, but if I did it again I would order it with the wiring incorporated.
As for tap shifting, I had to remove my TCM and send it in with my E38 ecm to get the tap shifting activated. I believe they need to reprogram to a corvette tune that doesn't send tap shift through the BCM.
No tow-haul mode available on these Gen IV conversions either, at least not from speartech and not yet.
Mine should be startable this weekend, finishing up the wiring. No reason to think it won't work from the wiring front, and I was very impressed with the speartech quality. Since they did the harness, programming, etc. I also have one place to turn to if things aren't working.