BCdawg57

iTrader: (1)

The harness is already disconnected from the motor, as the motor is no longer in the engine bay. I cant figure out how to dissconect the harness from the car.
From what i can tell the wires go back along the passenger side fender and down past the firewall, i see what i think is the computer in the passenger compartment. How do i remove the harness intact without cutting it?

Thanks
Jake

Z28ricer

iTrader: (2)

Under the passenger side of the dash you'll find the computer tucked up inside it, if you havent already unbolted it, theres a plastic bracket it sits in, this is retained by a post at the top going into a hole in a bracket up top, then the lower end is bolted to the dash rail, two 7mm bolts, when you remove those you'll be able to slip it out. Unplug the computer and the clear/black engine harness to chassis harness C207 connector. Remove the passenger side kick panel, you'll see where that harness goes through just ahead of the door, sometimes the housing there is just held in with the slide lock retainer, you should see it, looks like a giant clip shaped like a stretched out U, some cars there is also a 7mm bolt for extra insurance, IIRC this is only the 90 or 91-92 cars, if its there you'll find it and should be able to remove it with a ratchet from the wheel well opening after removing the plastic fender liner. Either way you want to remove that as there is a plastic retainer to keep the harness captive in there. Once you've got all that undone, that bulkhead housing has push tabs that lock it in place, push one down and you'll be able to angle it out and free, feed everything through that hole. back inside the engine bay, you'll find that housing hardly wants to go through the cutout by the a/c box, but i assure you, if you turn it just the right way it will come through there.

The other end of the harness by the brake booster has a 1/4" or 7mm bolt in the center of that black connector, remove it then you should see how to seperate the engine harness and headlight harness connectors from each other.

BCdawg57

iTrader: (1)

Wow. Great post, very helpful!

BCdawg57

iTrader: (1)

A couple questions.

By where the main part of the harness goes past the firewall on the passenger side, there is a connector that connects the main engine harness to another small harness with like 3 or 4 connectors that plug into a few things on the fire wall. Do i need to remove this also? I dont know if i need to keep it, or what they are for, But i am doing the LT1 swap with an LT1 wiring harness.

On the side with the headlight harness, do i need to take the headlight harness out or is there a way to dissconnect it from the main engine harness? Edit: i saw you said there is a way to dissconnect it but, I cant seem to find a connector.

Also, there are 4 or 5 of these small black boxes that have several wires going into them, but they dont seem to lead to anywhere. there are 3 or 4 on the dirvers side by the firewall, and 1 that i can see on the passenger side. The one on the passenger side is part of that harness that dissconnects from the main engine harness.

I know this is all sounding confusing but i dont know if it is all required to be removed or if i should keep it to have everything working correctly when i drop the LT1 in.

Thanks for any help.
Jake

Z28ricer

iTrader: (2)

Im quite certain you're talking about the engine harness connection to the a/c setup harness, you should have a rectangular black connector, has 3 wires, 2 of them about 12ga, one 16ga, it can be disconnected there, this is where the blower motor itself gets power and ground from, it also is where the a/c control panel signal comes from for the a/c compressor to turn on.

You first have to remove the bolt in the center to disconnect the pair from the firewall, once its free, you'll see there are tabs around the edge to seperate the smaller headlight harness connector from the main engine harness, the main bigger connector has sort of a cage that captures the other connector.

Sounds like here you are referring to the relays, those are for the fans, and fuel pump, the drivers side ones you can either unplug the connectors from them, or just unbolt the relay bracket from the firewall and take it out with the harness, the one on the passenger side should be mounted on a bracket to the a/c box, this is for the a/c blower motor, leave it in place and connected to the a/c harness.


The harness for the LT1 doesnt have half of the items that you'll be taking out, this is where the wiring for an LT1 swap comes into play, you have to build it all back into the 4th gen harness to be compatible with the thirdgen.
There is more that is required that is part of the thirdgen harness which isnt in the LT1 harness, power wiring, starter wire, etc.

BCdawg57

iTrader: (1)

This i assume is your a/c setup harness, i did what you said, and just disconnected it there.


I figured out how to seperate the two harnesses, and the one i am holding in this picture is the headlight harness im sure, case thats where i traced it to.
This is left in place correct. And stays in the plug that it was in orginally?

I just took off the bracket with those relays on it. And when i sell the motor those just go with it. correct me if i am wrong.

Oh and while im thinking about it, im not keeping any emissions on the LT so i can get rid of that charcoal canister correct?




What is this? this is supposed to stay pluged in right? it is on the same harness as the headlight harness.


I am getting my new engine harness from Speartech. So im sure a bunch of t his stuff you are saying that i need to re integrate into the 4th gen harness will be done by them. Like the fuel pump relay ect. I was looking at the layout for an LT1 harness on shbox's site and i noticed there are no fan connectors on there, this also needs re integrated with the 4th gen harness?

One last thing, i got rid of the EGR valve and low oil sensor switch on the LT1.
I can have the harness made without the egr valve connector and the switch i know, i assume the egr solenoid also. Anything else i should know about?

Sorry for all the questions. I have done alot of reading and im pretty much learning as i go here so please try to bear with me.

Z28ricer

iTrader: (2)

I dont know how complete the harness you are getting from speartech is/will be, so i cant tell you what you'll need to add.

I wouldnt get rid of the vapor canister or its solenoid, because its to burn fuel vapors, and keeps your car from smelling horribly of raw fuel at red lights, but hey thats just me.

Just curious, how much are you paying for this harness from speartech ?

BCdawg57

iTrader: (1)

They are charging $650 for theirs.
How much do you charge?

About that last picture again, can you tell me what that is?
And if that headlight harness stays plugged in there with the new harness, and what about the other half of that plug?

Z28ricer

iTrader: (2)

I've got a few different options, kinda hard to compare when i'm not sure what you are getting, it almost sounds like you're getting a harness with the power wiring etc for the thirdgen that plugs into the LT1 harness you have ?

Z28ricer

iTrader: (2)

Looks like you are talking about the pictured windshield wiper motor, and its connections, yes on 90-92 cars the wiper motor wiring is part of the headlight harness, earlier cars its part of the engine harness.