The wire harness was a lot more involved than I had anticipated, I would say this was more involved than the K2500 stuff I did.
The Cavi PCM is mounted on the passenger side right behind the headlamp inside the fender. So half of the wires are automatically 1 mile longer by default. At the moment the harness is complete between the engine and PCM, just have to interface the Cavi engine harness to this one. I ended up grabbing some 16-pin wiring pigtails and another 10-pin from a random 2010+ car at the u-pull, at the moment I have 36 wires for that connection, I might try to reduce that to 32 by consolidating grounds and +12v supply wires. I had to add two relays to the relay center for the radiator fans, luckily there were two relay spots vacant. I ended up having to relocate the battery to the trunk as well. I was trying to avoid that, but the space limitations in the engine bay are calling the shots now.
What's left:
-body harness to engine harness interface
-exhaust from the downpipe back
-random plumbing and hardware
-fluid fill
-put the interior back together because I had to put a different shift cable in and that...snowballed...
Unknowns:
The Cavi has what appear to be an early LAN class 2 data communication circuit (I would call it primitive, but I've actually worked with the 1986 Riviera computer and the 180 baud magic). The various modules are connected in a daisy-chain configuration with the BCM apparently the master. Every module connected has two class 2 data lines connected to it, including the PCM. From what I can find, every single module both of the wires are internally directly connected on the Cavi stuff. The Cavi harness does not have the UART wires (though depending what section of the service manual you reference, they are in the wiring diagrams). There's a ton of data and requests that are communicated via the class 2 buss, A/C request and gauge cluster functions to name a few. My initial research into this project said people used the Regal PCM OS (or I think the Monte Carlo SS one) and "just hooked up the wires and it worked". Of course, I can't find the original forum/built thread for that info. Anyhow, the Regal stuff has a single class 2 data line going to each module, they all connect to a single splice. The working theory is that the daisy chain approach to wiring doesn't actually matter beyond providing multiple paths to the master module to mitigate potential failure, and actually potentially reducing the total length of wiring used. What's also fun is that depending on the CSM you reference for the 3800 (or in the case of my '98 H-body CSM where one page says one thing and another page says the exact opposite), either of the two effected pins on the PCM are used for class 2 data. So, hopefully the HVAC, gauge cluster, ABS, sensing module, and BCM all play nice with the 3800 PCM when connected in the daisy chain config.
More details:
Since I'm told it was brand new, we'll see how well the fuel pump keeps up. Not planning to change the fuel pump at this time, going to monitor fuel pressure and see if it's needed. From what I can find, this pump has an identical flow rate to the NA 3800 pump, which seems to keep up with some of my previous builds, but who knows how accurate some of that published info really is.
Will the A/C work? I had to modify the compressor manifold from the donor Riviera to splice the cavi lines to it. I used an AN union + nylog on the intake side and a weld-on fitting for the discharge side, only had to crimp one hose. I've done similar with the Montana, and that works fine. The compressor and the class 2 data buss functions are the only concerns, I have a work-around for the A/C request to the PCM, the A/C from the donor worked so the compressor should be good. But with the level that this project is I'm still on the fence whether to send it as is or send the manifold I made in to a shop that can make custom A/C hoses and have them make one with some minor tweaks so there are no welds/splices and some tighter clearances to the compressor, and just put a new compressor in.
ICM is relocated to about the same location as an LG3 (above the rear valve cover) since there's not enough clearance to leave it on the OE bracket. I managed to move it without changing the wire lengths on the ICM harness.
EGR is retained. In order to fit the EGR valve, I had to swap the brake master cylinder to the N-body master. N-body and J-body for 2000 use the same brake booster, so this should be drop-in. The reason is the brake lines on the N-body come out the opposite side, so in addition to clearance, we won't have to worry about heating up the brake fluid in the lines. The EGR heat shield had to be modified slightly, squishing it down tighter to the EGR valve, to clearance the master cylinder as well. I ended up moving the ABS module over as well to keep all the lines accessible.
EVAP is retained, I only had to mount a purge valve in the engine bay and make the hose and wire connections.
MAP sensor was relocated to the front cylinder head, similar to what I did with the Montana, in this case it was because the ICM now resides where it usually lives.
Cruise control is wired up, though I don't know if it was working before. I don't know how picky the cruise control module is, the 3800's I've all had after a swap never work again, so I'll give it a 15% chance at best.
Upper radiator hose: E71947, my recollection is that it's a 2000 Malibu V6 hose, was a direct fit.
Lower radiator hose: Ok, not very happy with this, so more to come. I had to make a custom manifold because clearance to the A/C compressor and manifold prevents an OE L67 lower radiator hose from working, and the overflow tank needs a tee off that line as well. I ended up building a manifold from 1.25" copper pipe and fittings, using half of the L67 hose and half of a C71765 hose (IDK what it's from, a go-cart?). Pictures are coming soon, but I would love to see how any other swap did this without an A/C delete. This is the other half of the reason I'm considering a different approach to the A/C manifold, just to get some more clearance in that area.
Heater hose fittings: Referencing the fittings on the tensioner that the heater hoses connect to. The W-body fittings point straight out, both hoses might kink over time and the one would be rubbing the A/C dryer. The 90 degree fitting from the H-body and E-body cars will fit on the upper heater hose and have clearance to the A/C dryer. I couldn't find anything from the factory for the lower that would clear the dryer, so I made one on the lathe with a pre-bent section of aluminum tubing:
Heater hoses: Two e87606 Dayco hoses. I had to trim them shorter on both ends to fit. Simple, clearance to the exhaust down by the bulkhead.
Throttle cable: Almost yes. Similar to the Montana and Camaro, I had to cut off the throttle body end stop from the cable and swap on the L67 plastics for the mount. The OE cavi cable is long enough and can be shortened slightly, plenty of room to make the L67 plastics fit and weld on the barrel fitting. That part is not done yet as I need to measure the throttle lever to make sure it has sufficient travel for the L67 throttle body. If the lever arm is too long, pedal effort will be high and the pedal won't reach the floor. If it's too short, effort will be too low and it won't open all the way. I think it's too long right now because it's matched to the 2.4l throttle body, but haven't verified.
Cruise control cable: 99 W-body cable will work though its tight. Not sure what other options there are that will work since most of them are a lot shorter than the W-body cable I found.
Shift cable: N-body AC Delco 22678830 will work, as will the console shift '92-'99 H-body cable (which is out of production and not obtainable aside from used parts at the moment). With the N-body cable you need the N-body trans bracket, weld it on to the 4t65 bracket about 1/4" further away from the shift lever. The N-body cable is an exact fit to the J-body shifter and firewall pass-through. The H-body grommet needs to be modified to fit the firewall, though appears to fit the J-body shifter and the 4t65 bracket. I opted for the N-body cable since I was able to get one new.
Battery: I Grabbed a Mega 250 amp fuse and holder, some 0 gauge THHN wire and junction blocks. The stranded THHN wire is going to be mostly rigidly mounted between a set of junction blocks in the trunk and under the hood. OE battery cables shortened to fit between the battery and junction blocks, and modified H-body 3800 cables between the block/starter and under-hood junction blocks. From the research I did, looks like the typical 3800 starter motor pulls 1300-1700 Watts, so I sized the long cables based off that.
Front Brakes: Cadillac JL9 (STS/CTS/SRX), 12" rotor, dual piston aluminum calipers, N-body knuckles and outer C/V hubs, N-body LCA ball joints. J-body WSS connectors fit the N-body bearing hub connectors. The brakes bolt up to the N-body hub without modifications. The hardest part is removing the old J-body ball joints; the N-body ones bolt right up to the J-body LCA. Using the N-body hub did not change the length of the axles I mentioned earlier, though the Cavalier Rpezza won't fit so I ended up using the N-body Rpezza on them.
Massages: The pinch weld flange on the frame structure needed to be clearanced around the power steering reservior and the belt for peace of mind.
So far, no deletes.
Other:
Looks like I've been tasked with an exhaust cut-out and some LED accent lights. I'll have to figure out the wiring for that before I put the interior back together.
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