i am on to the worst part of the lsx swap! and i need help with the wiring!! i have cut the drivers side harness off at the firewall and need to know which wires need to be connected to the 4th gen pcm wiring harness?! what color wires are the swithed power and the always on power on the pcm harness itself? i just need to know the 5 wires to get the engine started and kicked over! i have the interior and accessories working but cant get the engine fired i just need to know those couple of wires!! HELP and thank you!!!

 

Not that I was considering becoming your personal research assistant and looking this repeatedly-posted information up for you, but a mention of what year your LS1 harness is might have been helpful.

 

I replied to ur PM. Bad idea to cut it off at the firewall. It would have been just as easy to remove it . U know it also contains ckts for ur gauges that u have to wire up.

 

The information is contained in the links in the LS1 swap sticky.

 

i took the advice and read alot and have wired up my own fuse box using the 4th gen relay box, question now is :
1. why is the purple starter wire coming out of the firewall not getting power when i turn it to the start position

2. where is the fuel pump relay, is the connector next to the a/c box on the passenger side? if so, can i just cut the red wire (power) and splice into a switeched source that is hot in start/run?

Thanks for the help!

 

1) is the starter kill relay still intact or have you bypassed it yet?

2) The fuel pump relay is located near the brake booster. Identify it by the red prime lead. Do not splice into the prime wire, wire the relay the way it was from the factory

 

the purple wire comming out of the driver side firewall connector should run directly to your starter wire. iirc, the purple wire on the 4th gen harness runs to the 4th gen fuse block to the starter relay, your bypassing that relay. If your not getting power to the purple wire in the crank position, then you have another problem somewhere else, meaning either you dont have something that needs power or you have another issue all together.

 

Did you do anything to/with the '92 VATS system?

 

Cutting the 92 harness off at the firewall was a bad idea...but moving on.

Give details of what u have for wiring ?

What kind of fuse box are u planning ?

Do you have LS1 firewall harness ?

 

i wired the relay box using the walkthrough of team third gen that was posted in the lsx swap sticky,so that is where i am getting switched power and everything so my 4th gen harness is getting power and interior has power but the only wire that is not is the purple 1 coming out of the firewall.......
i did nothing with the vats system on the 92, and my friend decided to cut into the 4th gen harness so i was not able to use any part of the firewall harness.
do i need to bypass the starter kill relay or is it another problem?

thanks to all for the help, hope to get it fired this weekend!!

 

If you havent messed with the relay, itll hold you up

Either connect the heavy gauge wires or ground the blk/yel wire

 

is the starter kill relay? if so i splice the green thick gauge and yellow thick gauge?

 

ok i figured it out it was the starter kill relay, and now i have power to the starter!!!!!!!!! woo hoo!!!! i guess it is on to the fuel pump relay..... then disabling vats which i bought 2 resistors that i will splice into the wire for vats to disable it.... then hopefully fire it up!!!!

 

you have to either build a vats bypass module for the ls1 pcm or tune it out. i dont know of any other ways to bypass it.

 

As far as swaps go, once you overcome the starter kill relay, 3rd gen VATS is done for

You have to tune the LS1 PCM to be rid of the newer VATS system

 

i just bought the vats bypass module to take care of vats....

http://cgi.ebay.com/ebaymotors/ws/eB...m=320392148402

 

Why?

The 3rd gen VATS is taken care of with one wiring change (join the wires or ground the relay)

LS1 VATS is taken care of via tune and you HAVE to tune the PCM to get the swap to work

 

so how do i go about getting my pcm tuned to the correct specs and how much am i looing at money wise?

 

Find any friend with tuner software or mail the PCM to a company who tunes LSx engines like PCMforless

Cost should be case of beer to $150

 

I told you i could have tuned your vats out for you before i delivered your swap to you for $100. You told me you didnt want to.

 

JET performance has a tuner package that works well, I am in the middle of tuning mind and find it has all you will need it also will remove the vats.