Specific LT1 wiring questions with pictures.

[JustChou]

So,

 

I've stripped and tagged the harness as per the pinout diagrams of Tim240z, and I still have a few questions.

 

It's probably the best if I go through all the connectors.

 

Harness starts at the ECM, and goes to the MAP sensor. Then I run into a cluster of plugs including a ground, ECT plug, and "ignition control" plugs. What is an ECT, and where does the "ignition control" plug go?

 

Then, the harness runs into injectors 1, 3, 5, 7, and moves onto a fork with the Bank #1 and Bank #2 HO2S, the IAC coil (which I'm missing), and a knock sensor. What are is the HO2S, and which bank is #1 and which bank is #2? What does IAC stand for?

 

The harness then moves to the even injectors, and once again branches off. This is where I'm really confused. There is a 2 pin connector, which I've marked as IAT (intake air temp?), and a four pin marked as Distributor. There is a mystery 3-prong connector that has blue, black, and red wires running to it.

 

I've mislabeled this the TP sensor. I actually have no idea what it is.

 

Is this necessary? Can I cut it? What does the red wire plug into? I believe black and grey are ground and +5 ref.

 

There is also an identical 3-pin sensor that I've marked as TP sensor. It has a grey wire, a black wire, and a dark blue wire. All three of these wires run to another connector, that's also plugged into the firewall junction block:

 

This is the real TP sensor, mislabled "?"

 

Do I need this thing? It looks like a data connector of some kind.

 

After that, there are just a few wires. A super long 1 pin blue wire that I've marked as a knock sensor, black with white tracer marked as check engine light (what voltage is this?), tan with black tracer marked as ADAL comp link (where do I plug this into?), purple "brake signal" wire, black with white tracer "ground," and tan "serial data wire." Besides that, there's a whole handful of of pink and orange wires looking for +12 that run into what looks like a massive fuse block. Should I mark and fuse all of these wires, or just connect all the orange to constant hot and all the pink to ignition hot? Is there anything I've done wrong?

 

Thanks for all your help,

Justin

[hanomon]

Justin,

What year model harness do you have?

Will you be keeping all emissions?

Auto or man trans? Cruse or No, AC or No?

OEM or aftermarket gauges?

Depending on what you want will determine how much of the wires will be used.

 

I've gone through every wire one by one on my 94' LT-1 reducing the ammount of wires by 25%.

 

I could send you the diagrams but only for a 94' Corvette vin-p.

I bought the factory Service Manuals (highly recommend) from the Chevy dealer where my Son worked. They are year and model specific. I paid $94.00 a year ago.

 

I'm sure if you were to aquire a set, most of what you'll need to know can be found there for your particular yr. A very wise investment.

 

To answer a few of your questions here now;

 

ECT=engine coolant temp

DLC=data link conector

TP=throttle position

IAT=intake air temp

IAC=idle air control

HO2S=hot oxygen sensor

 

As for banks 1 and 2 are pre and post Cats, or perhaps even and odd cyl.

I don't have the books in front of me (in the office) and my memory fails.

 

I may provide more info when I get home and refer to what I have.

In the mean time...

Hope this helps.

 

Hano

[JustChou]

Let me see...

 

I have a rather exotic harness, from a 94 Buick Fleetwood, the Buick equivalent of the LT1 Caprice. I am not keeping any of the emissions, I am using a manual transmission, no cruise or AC.

 

I'm building a completely new dash, running autometer gauges all around.

 

Thanks for the info about the few that I haven't identified - I actually have a factory service manual, but it's from a 94 Camaro.

[240playtoy]

I've got a 95 Cop Caprice harness and ECU and am slowly going thru it. Got some Alldata for the thing but nearly impossible to locate the Wiring diagrams there. Anyway, bank 1 and bank 2 (if like the F-body's) are left and right O2's respectively. I ran into the mystery connector as well w/ a 93 harness. If I remember right, there's an ECT (the ECM coolant sensor) and a temp sensor (to the instrument cluster). The mystery box, if it's like mine, holds fan , A/C and AIR relays, ECU and A/C fuses and a few other things I can't remember.

Again, all wiring is from my Caprice wiring diagrams. So, your "Red" grey and black may be the A/C pressure sensor if the red wire is infact red/black (according to wiring diagrams) The TP sensor should be dk blue, black and grey and the black and grey wires should go to other sensors, grey to the A/C press. sensor and black to IAT and A/C press sen. Knock sensors should be dk blue. AS for your light blue, the only wires I came across that were that color had white or black striping and went to the Idle air control.

Ignition control, most likely your ignition coil module 4 pins, white, white/black, pink/black and black/white. If they are a pair of connectors (black and grey) each with a pair of pins (wires might be pink and something? and pink/black and white/black respectively) then it's your coil connector. If I remember right, the ignition coil should have 3 places to plug things in, the pair side by side and the 4 pin.

 

I hope this was of some help, if you still needed it....

[Tim240z]

There should be a connector for that plug pictured above down behind the water pump....kinda hard to see.

You don't need anything from the main harness (with the fuse block). I believe the OBDI connector is completely seperate. i just went to the JY and pulled one from another GM car (a cavalier, I believe).