smokin91rs

aright guys ive got a 99 ls1 auto 4l60e relacing my 305tpi auto in my 86 TA, i read these fourms for hours and looked at the wiring diagrams but have some questions with the ignition wiring, do i use the old or new battery connections to starter? and maf,fuel,burnoff relays, i need to use all these old relays- which means destroying my tpi harness to seperate everything? i maye be over thinking this but if anyone has there notes or anything that can simplify this i think there a lot of us that would apperciate it. ive seen every diagram for the ls1(they say use these wires only on connectors c101 ect.) but all that i see for the tpi is, hook the pink wire(he one harnessed with the tach) up and guages. -thanks

85irocinjected

First of all, there is no relay for the maf its directly hooked to the PCM. If your using a 4th gen tank then you just wire the power for your fuel pump with the corresponding wires from the PCM to a relay then to the pump. (That way the PCM can start and stop the priming and what not). I did not use any of my original harness except for the part which comes from the drivers side. I still only used about 4 maybe 5 wires from there just because they are already fused and I just hooked up what I wanted...To make life short and sweet with the install just take the 2 ORANGE wires from the plugs near the RED and BLUE PCM plugs (C100,C101,C105, 220, 230 - cant remember exactly which plug buts theres only 2) and the 6 PINK wires from those plugs also, FUSE them and the car will run. Also I took the PURPLE wire from the LS1 harness that comes from the starter and just cut and spliced it into my original PURPLE wire (Thats the ignition wire).

smokin91rs

hi, thanks that cleared up a lot for me i was 99.9% sure i didnt need the old tpi engine harness but i read some were about using the old relays and got all confused, thanks for clearing it up, now it should be running in a few days

chevy_camaro_ss

iTrader: (4)

Wow is that simple or is there more to it? Would that get it running back and forth?

85irocinjected

Its that simple..That is how I wired mine and I have been driving it for about 2 weeks now everyday. Of course you will need to bypass VATS (which I did) or just delete it from the PCM (which I did a week after driving with my bypass) and you'll want to hook up some gauges to keep an eye on the temp and what not. I think the gauge wires are on 220 and 230..Can't remember exactly though.

jak2908

how much different would that be on a tbi harness??

chevy_camaro_ss

iTrader: (4)

So if your using a third gen tank then would you wire it to the LS1 PCM or just to like a relay with a switch?

85irocinjected

If you use the 3rd gen tank than just leave the wiring alone..It goes to a relay right. I am using a 4th gen tank and just wired my fuel pump through a relay. I plan on wiring through the PCM just have yet to do it.

Jak, you do not need to use the engine wiring harness.

chevy_camaro_ss

iTrader: (4)

By any chance do you have pics of the wires you "Fused"?

jak2908

has anybody seen the LS1 install in a 3rd gen in the new camaro performers magazine????? the wiring in that is sooo simple speartech.com does the wiring harness...a total of 18 hook ups including your tach, coolant temp, and ignition so ya...it just plugs into your stock wiring harness

cam-

Theres a few grounds that have to be hooked up as well

85irocinjected

The only grounds I hooked up where the one from the battery to the engine block (right above the starter) and a ground strap from the engine wiring harness to the car frame. Other than that there where no other grounds I used.

cam-

Theres at least one ground for the PCM. Pin E of the white 220 plug.

Grounds are sketchy... In your case its obviously running but you cant have too many or too good of a grounding system. 9 times out of ten automotive electrical problems are the ground/s.

I think I hooked up about five in total being a factory carb going to fuelly swap and all. Not to mention about three off the engine/chassis/battery to keep everything happy for a loooooooong time. I redid the entire system fresh figuring it was wise being a twenty year old car.

MrDude_1

http://www.ls1tech.com/forums/showpo...7&postcount=13

http://www.ls1tech.com/forums/showth...ght=connectors

chevy_camaro_ss

iTrader: (4)

Is there any chance to get a write up with some pics? I also have and LS1 wiring hirings from 2002 camaro but I only got the harness that comes out of the passenger side that connects to computer. Is this all I need.

cam-

Understanding your situation clearly as I was recently in your shoes myself I will explain as best I can. It seems very daunting from the outset to figure this out but the best advice i received ( thanks MrDude ) was Dont try and figure it all out in your head first its a futile approach. Take it one wire at a time and dont leave it until its connected or deleted. What I did for this was as follows;

Figure out what every single wire in your engine compartment is and label them. ALL of them. You can source the info online ( google searches, forum searches etc ) or through a service manual for your car. I found all mine online searching around and printing out everything and comparing.

Once you have all of those labeled and understood do the exact same thing for your engine harness.

Then decide what you need to keep and what you need to cut. For instance maybe your using the AC and maybe your not. If your not cut them out from both harnesses. Do this for each wire until all thats left is what you want to use. Obviously things like computer power and injectors etc need to stay. Most of the rest is optional. Read MrDudes links it explains it clearly.

Once you have whittled the pile down start with one wire at a time and splice it in to wherever it needs to go and repeat til your done. Its very straight forward. Good luck!

chevy_camaro_ss

iTrader: (4)

I guess your right. It will more clearly to me when I set in the harness. I will try your approach. Just one more question please. The main part I need for the wiring is the harness connecting to the computer from LS1 and maybe a fuse box and some realys right?

cam-

You do need to add a few fuses in there. Anything that hooks to ign or battery needs a fuse. In my case I also needed to add a complete fuel system as my car was a mechanical fuel pump prior to the LS1. I used a plastic fourth gen LS1 tank for my pump and regulator that is awol but thats another story...

I purchased a chassis harness ( The thing that has the correct 5 corresponding connectors on your engine harness that has fuse boxes and relays for the whole fourth gen car ) so I could utilize the fuel tank plugs and the LS1 engine harness to my cars harness thinking it would be great to have the connectors all factory like etc. Plus I figured I would just use the fuse boxes and relays from the fourth gen chassis harness and leave the other ones along for the ride thinking cant hurt right?

In the end it turned out so simple I chopped one of the two fourth gen fuse boxes out ( there are two stock ) and reworked a couple of fuses to fit my needs and used the relays for my fuel and fans. The connectors off the chassis harness i ended up cutting off because they were rather large and i was only using a few wires from each of the connectors and wanted it nice and neat so waste of time on those.

Knowing what i know now I wouldn't have even bothered with the chassis harness as it made more work for me and although i am very pleased with the overall result in terms of function and appearance I could have done it in a fraction of the time if I purchased a nice after market five block stand alone fuse block and a couple of new relays and just made up my own. I think you only need three new fuses if your car is already injected from factory. Dunno you'll hafta confirm that.

For extra wire I salvaged a harness out of a couple of cars from the wrecking yard for cheap and got my OBD2 port etc. This way all the wires I have are rated for the job and same colors even after splicing.

To connect I used rosin core solder, heat shrinks, harness tape ***Note this is NOT electrical tape its harness tape rated for high heat*** and weather pack connectors ( again from spare harness bits ) And finally used the stock GM plastic conduit wire coverings to neaten everything up. Looks like new and completely factory. No issues worked aces right from day one. Hope this is of some help

N8MAN1068

I keep hearing about this harness, but can't find it on their site. Is it not available yet? Do you have a link?

jak2908

im not sure witch one they used but you could probably call them and see how much the get for them and what it takes for them to do it...if you do, post back and tell us what u found out!

cam-

Speartech is sponsor on LS1tech. Lots of info there about him there and a link to his site. No sponsor here so no linky from me.

That being said although his stuff sure looks nice and he is a great guy its too pricey for me considering the difficulty of doing it yourself.