Quote Originally Posted by Mickeymotormount View Post
I actually wanted to use the '99 cruise module. I took it from the donor truck but it was defective. After multiple attempts to wire it and not have it work, I figured I'd try the '93 module originally equipped with the truck. It ended up my original wiring was correct and made the '93 module work like a charm. What I can do is pull out my '99 service manual, scan the cruise control schematic, and then post it here. Hopefully this will help you. It has been about 3 years since I swapped engines so things are a little fuzzy.

The reason the PCM is involved with the cruise in the first place is that while in cruise, the PCM alters shift patterns so there is seamless performance while in cruise control. If you have 4 wheel drive, there is also a 4 wheel enable wire that lets the PCM know when the transfer case is in Low gear. This allows the PCM to shift the trans while the transfer case is in low gear. Originally, I left this wire unconnected, later to find out that, while in the transfer case was in low range, the transmission would not shift out of 1st gear. Hooking up this wire to the transfer case low switch allowed the PCM to shift the trans while in Low gear range.
Oh I see. I have a manual trans so I ended up just removing all of the transmission wiring from the LS harness. I will be using the 95 cruise module. I'll report back on whether what I did works or not. It would be nice if the electrical diagrams also included the type of signal that each wire had. It would make this much easier.

Sorry for the thread jack OP