I'll answer what i can,
I have been doing some planning on the wiring. I am using the guide on lt1swap.com. I still have questions on some of the connections.
The stock 87 fuel level sensor is a completely closed system going to the gauge correct?
Yes.
After a tune, the engine will run fine not seeing the 5.3l stock coolant temp sensor? or do I run that sensor and add my 87 sensor to the block for my dash gauge?
You need to add one. A few ways of doing it. On is to get on ebay and search "ls1 temp sensor conversion" or something like that which will produce a three wire temp sensor with pig tail. That single sensor will run both the computer, and the gauge. Option two is to take your trucks stock temp sender and turn it down to the 12x1.5 thread pitch and stick it in the hole thats on the passenger head on the back. There are a couple other options, but i would say those are the best/most popular.
Ok, using 2 makes much more sense.
Can I add the electric fan control wires for now, not actually use them by just capping them off (clutch fan for the time being)?
Shouldnt be a problem. Might set a code? But i wouldn't imagine so.
Blue, C1:
33- TCC brake switch - needed with 700r4? I am assuming that I can just remove it?
I would think you would need it for torque converter unlock? I dont know.
Hmmm... I was wondering what was hooked up to the factory TCC lock up switch. I guess if the computer controlled the old, it would need to control the new as well.
It was marked red (remove if not using 4l60E) on LT1Swap.com.
34- PRND P input - worth using as a park / neutral saftey switch hook up? Is that even possible with my 700r4?
You send that a signal from the neutral safety switch thats mounted to your steering column by the fire wall. Most would say to do it and i would agree, although i have been running mine without and its been fine. THe main issue is that it will try to idle at the same RPM in both drive and park.
Using the pin 34 wire would eleminate the harsh shifting into gear then, correct? I also like using an integrated P/N saftey switch from the saftey inspection stand point. Also, it would potentially make a great kill switch. If the computer was still programmed to look for it.
71- Tow /haul button - I assume I dont need this due to having control of my trans through OD/D selection.
Yea thats only a trans control thing. Scrap it if your running the 700.
Cool deal.
Red, C2:
10- engine speed tach output - I can just hook this to a Tachometer (RPM) gauge corrrect?
This is anotherone where some witchcraft is involved. Sometimes hooking it right up to the tach is good, and sometimes you need to run a "filter". Either way, it only sends out a 4cyl signal. So if you have some kind of aftermarket tach, you have to switch it to 4cyl mode. On my boddies truck that we just finished, he was able to take a wire straight from this pin, to his sunpro tach on 4cyl and ot worked right off.
I have read about a few of the tricks to use and how programmers can set it up to run diffrerent signals. I will just plan on him running a 4 cyl signal and get an approritate tach. I was just wanted to make sure that is the wire I run to the gauge.
11, A/C high press recirc. switch - Worth keeping if using the 5.3L AC comp?
Dunno. Wouldnt think so.
13, Cruise control engauge - Able to adapt the vacuum C.C on the 5.7 to a 5.3?
Yours is drive by wire right? Then all your cruise stuff is seperate. Its all left overs from the 87 and you use nothing at all from the vortec setup. Drive by wire is different. It uses a mix of vortec stuff and existing stuff.
No, Sir. All DBC setup. I figured if it worked on the DBC 350 and is vaccum modulated I dont see why I couldnt run it on the 5.3l. Shoot even on my Wife's Mazda P5 the cruise is vacuum controlled.
I guess the main hurdle is seeing if the PCM has any say in the old cruise system. If it is I dont think i will be able to adapt it. Any good resources for info like that? Or good diagrams for our old trucks? Im not having much luck finding good diagrams for our old trucks.
17, A/C requst signal - If keeping A/C of any kind I assume I keep this. No idea how I hook up the factory 87 A/C controls.
A/C is the same as cruise. Its all seperate entaties. Just like they were originally on the 87. Treat it as if these pieces of equipment never left the engine compartment and now you are just adapting them to fit on the motor. KNow what i mean?
Ok, cool. I will just follow along with LT1Swap.com and pull out any and all 5.3l A/C related wiring. I thought maybe the PCM on the 87 controlled A/C stuff and it needed to be switched over to the new PCM system. Especially using the new compressor and all that. If it isnt run by the old PCM and is just switches and power then that should make it easy I suppose.
43, A/C clutch relay - ??
Same as above. You wont be using the Computer to run the A/C. However, if i remember right, there is a signal feed of sometype that you can give the computer to let it know A/C is on and it will edge the idle up and turn on one of the fan relays, but you will have to do a little googling on that.
50, Vehicle speed output circuit 4k - Assume this is what the cable VSS adaptor goes to?
Dont quite know for sure on that one.
55, A/C low press switch - Seems like a lot of people pull this off. Why? keeps your A/C from destroying itself.
Because your truck still has its low pressure switch. You would use this if the computer was controlling the AC.
Does any of the EVAP / Purge stuff effect the fuel pump at all? Is that stuff strickly all emissions / carbon foot print related?
As long as you dont plug a vent or anything, its all good.
If talking about blocking factory 87 tank vents and stuff, I dont think it has any.
So I guess I will just pull off all that crap and plug it on the new 5.3l.
Hopefully none of that made me sound like an idiot.
I think the yard put them on, they offer some type of 31 day garuntee. I think its just so they can deny a warrany claim if the tag shows it was overheated.
