I would agree that those are two items I’d like to keep as well. I just saw my truck for the 3rd time this year if that gives ya an idea on how much time I have for it, quite sad. Just keep buying parts and stacking them in the bed. One these days I hope I can start spending some time on it.

 

Well an update on some theories with my electrical mastermind as the install will be starting here soon...

A/C - One of the pressure switches gets replaced with a trinary which turns on your cooling fans. I think it can also be done using a Holley output, I'd swap the pressure switch.

Blower speed/Temp/Vent controls - Just need power and switched power, which should come from the ignition switch as it is. Looks like as far as the AC is involved its just sending out an AC request so the pump kicks on.

BCM- The wiring diagram seems simple. But it also gets serial data from the ECM. So not 100% sure what happens when it doesn't see that data, but that may not matter if its not controlling anything engine speed dependent. So dome lights and all that stuff "should" still work.

Cruise - It's just a servo motor and guys put them in everything as long as it has a usable speed signal. What I would like to figure out is if we can just piggy back the output speed sensor on the trans and feed it directly to the servo instead of tying up a Holley output to do it. The trick will be figuring out what to feed power to make the factory stalk switches to work if/when the BCM decides its not cool with no serial data. Worst case, we swap the servo to the Camaro version that most people use.

NSS (Neutral safety switch) -. Just leave whatever version that truck uses where it is, break out the NSS wiring from the trans harness and leave it be. The range selector just has to ground the relay so the starter see's power.

 

So.... two weeks ago I decided to replace the ls1 fans with the 34” radiator and newer trucks fans and now...

I have truck that no longer has the OEM ecm, t2 connector (fuse box) and harness completely removed from the truck as of today. So we decided to see what the truck was going to do less this harness, meaning what OEM components would still work. Hooked the battery up and I still have all blower control functions, assume hot cold control but could not test, the actuators changed vent location. So very happy with that! Appears though headlights were affected as they are not working correctly. We believe the BCM needs to be tricked/grounded through the switch and they should function. May lose the auto headlight on but I’m old enough to remember cars/trucks you actually needed to do that in order to make your headlights work.

Another awesome find we believe is the Current Performance appears to have an A/C harness that is plug and play for the Holley!! Still need to use an output but that’s what they are there for. Going to order the Sloppy Flex harness, and some other sensors that I need but made good progress! I’ll be putting a hole in the floor where the OEM manual shifter would go to run the Holley harnesses through that way I can run the + - power to the rear for the ECU and that engine portion right up about the bellhousing. So making some headway!

 

Man time flies... well last night was finally the night after minor annoying setbacks, it is running on the Holley! Took 3 starts and holding the pedal to about 1100rpm but then it idled on it's own and started learning. However it is insanely rich as it is trying to learn so I had to shut'er down til I can back it out of the garage and let it run outside. The 6.86" Pro Dash looks baddazz with Atomic's dash plate!! Bittersweet however as it will be put up for storage til spring here very soon. Just didn't plan for those stupid minor setbacks and wanted to enjoy it a little more.

 

Congrats, that is still a big milestone

 

Thanks! I actually should edit the title as the stock ECM and entire wiring harness is no longer present. So really I just kept the few functions that the BCM ties into (i.e. headlights) and also kept the OEM fuse box which we ran the fuel pump trigger from the Holley and the OEM starter solenoid wire. The fuse box still has the body wiring that I hope to be able to just leave alone.

 

I know I'm digging this up from the dead but can you share any detail on what you did to get the headlights functional? I'm working through this exact scenario currently.

 

Did you get an answer or figure this out yet. Also in the same boat and I’m having issues with the headlight functions. Appreciate it!

 

I'm still working on the truck and this is down the list of thing to get to. I recall getting them to work with some testing but not exactly what I did. Ill report back when I do final wiring.

 

So all I ended up doing was grounding B7 pin on the c2 fuseblock connector straight to the battery. That along with good body and chassis grounds allowed everything on the interior and all exterior lighting to work.