OK want to rewire my car after solid rear swap, need advice, who has rewired an LT1?
07-25-2008, 05:44 PM
#1
Melting Slicks
Thread Starter
Member Since: Jun 1999
Location: Bowling Green KY
Posts: 2,948
Likes: 0
Received 21 Likes
on
16 Posts
OK want to rewire my car after solid rear swap, need advice, who has rewired an LT1?
Guess today is my day for questions to the forum. 
Now that my solid rear is all done, I'm wanting to completely rewire my car. My wiring is pretty much a disaster right now - myself and previous owners have hacked it up pretty good. Stock fuse box is toast I think, at minimum I want to start with a fresh one.
My problem here is, I don't know squat about electronics/electricity/wiring (though I am comfortable with the tuning side of things) so not real sure where to start!!!!!!!
My buddy (who has done plenty of wiring stuff) is gonna help me rewire the car so I'm not too worried about it but wanted to get the ball rolling here. Most of you are familiar with my car and I'm really wanting to turn this thing into a C4 showpiece so I want to do this right.
The car is running fine right now though I think the fuel pump relay is going out.
Here's a quick rundown to give some background from an electrical standpoint:
Car now has no A/C or heat so no problem there
No ABS
External Aeromotive fuel pump
Autometer gages so I'm getting rid of the stock display
I may want to do an LSX swap in the future so I want to basically completely separate all engine wiring from everything else so that I can easily swap motors and/or engine harnesses and not really affect the rest of the car.
Basically you can look at this like you are wiring a street rod kind of.
I'm thinking all I really need to do is buy a Painless Wiring EFI fuse box and start from there? My only concern with that approach is the PCM, I have no idea what is needed in that regard. I do have VATS disabled in the PCM which I "think" should allow me to unplug the CCM and the car should run fine (haven't tried it yet). But I absolutely want to get rid of the CCM, I don't need it now but I still need the horn, courtesy lights, etc. so I'm thinking a nice simple aftermarket fuse box is the way to go, something like this:
http://store.summitracing.com/partde...5&autoview=sku
I'm thinking someone here has done this, I may crosslink over in the racing section
All feedback appreciated for this electrical idiot . . . . . .
Now that my solid rear is all done, I'm wanting to completely rewire my car. My wiring is pretty much a disaster right now - myself and previous owners have hacked it up pretty good. Stock fuse box is toast I think, at minimum I want to start with a fresh one.
My problem here is, I don't know squat about electronics/electricity/wiring (though I am comfortable with the tuning side of things) so not real sure where to start!!!!!!!
My buddy (who has done plenty of wiring stuff) is gonna help me rewire the car so I'm not too worried about it but wanted to get the ball rolling here. Most of you are familiar with my car and I'm really wanting to turn this thing into a C4 showpiece so I want to do this right.
The car is running fine right now though I think the fuel pump relay is going out.
Here's a quick rundown to give some background from an electrical standpoint:
Car now has no A/C or heat so no problem there
No ABS
External Aeromotive fuel pump
Autometer gages so I'm getting rid of the stock display
I may want to do an LSX swap in the future so I want to basically completely separate all engine wiring from everything else so that I can easily swap motors and/or engine harnesses and not really affect the rest of the car.
Basically you can look at this like you are wiring a street rod kind of.
I'm thinking all I really need to do is buy a Painless Wiring EFI fuse box and start from there? My only concern with that approach is the PCM, I have no idea what is needed in that regard. I do have VATS disabled in the PCM which I "think" should allow me to unplug the CCM and the car should run fine (haven't tried it yet). But I absolutely want to get rid of the CCM, I don't need it now but I still need the horn, courtesy lights, etc. so I'm thinking a nice simple aftermarket fuse box is the way to go, something like this:
http://store.summitracing.com/partde...5&autoview=sku
I'm thinking someone here has done this, I may crosslink over in the racing section
All feedback appreciated for this electrical idiot . . . . . .
07-25-2008, 09:06 PM
#2
Race Director
Member Since: Sep 2003
Location: Database Error Indiana
Posts: 16,617
Received 232 Likes
on
164 Posts
I have a little time invested in wiring my 71 Nova. When I got it the only wire in it was a ground cable. I would make a list of functions that are keepers. One thing I suggest is, do not hack the harness in the collumn. If you want to retain signals, horn, wipers the stock stuff in the collumn is hard to beat. If you can retain the stock fuse box, and remove the wiring you do not need, whats left may not be that bad to deal with.
07-25-2008, 10:38 PM
#3
Melting Slicks
Thread Starter
Member Since: Jun 1999
Location: Bowling Green KY
Posts: 2,948
Likes: 0
Received 21 Likes
on
16 Posts
I have a little time invested in wiring my 71 Nova. When I got it the only wire in it was a ground cable. I would make a list of functions that are keepers. One thing I suggest is, do not hack the harness in the collumn. If you want to retain signals, horn, wipers the stock stuff in the collumn is hard to beat. If you can retain the stock fuse box, and remove the wiring you do not need, whats left may not be that bad to deal with.
Thanks!
08-01-2008, 04:15 PM
#4
Le Mans Master
wiring
I would go to Summit racing, and buy an engine harness for an LT-1 to fit anything, add the longer wiring so you have an extra 6 feet of it, and use the under rear cargo area storage for your electronics bay (MSD box, engine computer, relay panel, etc.). then when you need to get at these items, you don't lay on your head looking up under the panel between rounds trying to troubleshoot with a flashlight in your teeth, you just pop the hatch, and pull out the panel you need with the relays and stuff on them. Then coil them up and store them for next time.
Be sure to buy the same type wire as the OEM's use, and buy an aircraft terminal splice and wiring kit with crimpers and strippers.
Do not use the pliers style of wire crimpers. The wires fall out of the terminals after a few cycles. And you can't pull on the wires at all.
Buy wire markers, and label every wire at each end. make sure the markers stay on, so that in the event of something not working, and you have a bundle of wires as bigas your wrist, you can find the wire you need in minutes instead of hours.
Aircraft wire is labelled every 6 inches, so no matter what panel you open up, there's the wire!
Of course the wire is all mapped out on a print, and each wire is stamped it's entire length before even being put in a bundle.
Then make yourself a notebook, make drawings of the car layout, and label each drawing, and If you are really ****, buy a cheap digital camera and include pics of stuff you don't think you will remember.
Be sure to buy the same type wire as the OEM's use, and buy an aircraft terminal splice and wiring kit with crimpers and strippers.
Do not use the pliers style of wire crimpers. The wires fall out of the terminals after a few cycles. And you can't pull on the wires at all.
Buy wire markers, and label every wire at each end. make sure the markers stay on, so that in the event of something not working, and you have a bundle of wires as bigas your wrist, you can find the wire you need in minutes instead of hours.
Aircraft wire is labelled every 6 inches, so no matter what panel you open up, there's the wire!
Of course the wire is all mapped out on a print, and each wire is stamped it's entire length before even being put in a bundle.
Then make yourself a notebook, make drawings of the car layout, and label each drawing, and If you are really ****, buy a cheap digital camera and include pics of stuff you don't think you will remember.
08-02-2008, 08:33 AM
#5
Team Owner
I'm doing mine and it is no fun. 
08-02-2008, 01:33 PM
#6
Le Mans Master
Member vstol has installed an LT4 in a '64 Grand Sport and has
had to work through some wiring issues - perhaps he might be
a resource.
My contribution here is to caution against using the commonly
available 'GPT' insulated wire for the project, especially in the
engine compartment.
From another thread:
GPT: -10°C to +105°C => +14°F to +221°F
TXL: -51ºC to +125ºC => -60°F to +257°F
In a simple test, a piece of GPT wire was brought close to the
flame of a propane torch. At some distance from the outer cone
the GPT insulation quickly softened and began to flow, exposing
the bare conductor. In contrast, a piece of TXL wire was able
to be positioned into the cone of the flame and held there - the
insulation on the exposed side charred and blistered but did not
expose the inner conductor.
The TXL wire used above was from bulk wire distributed by Painless.
However, you can reproduce the test for yourself if you happen to
have an in-line fuse with the thick orange insulation such as these
ones available from NAPA.
These f-holders have either the GXL or SXL version (wall thickness?)
of cross-linked insulation. Hold a piece of this up to the flame and
compare the results with what happens to conventional GPT wire,
then decide which is most suitable for your application ...
.
had to work through some wiring issues - perhaps he might be
a resource.
My contribution here is to caution against using the commonly
available 'GPT' insulated wire for the project, especially in the
engine compartment.
From another thread:
Some thoughts to keep in mind in case you do slide down the slope
and need to create your own wiring harnesses.
Be aware that the conventional automotive wire available from
jobbers is marked as GPT (General Purpose Thermoplastic). It is
typically good for only -10°C to +105°C. This just won't be sufficient
for underhood conditions. Maybe worse is that its Polyvinyl
Chloride (PVC) insulation will flow away from a load, this means
that it can eventually expose bare wire at points where it passes
through a bulkhead or is zip-tied to something.
For your wiring, consider hunting down conductors (wire) with
cross-linked polymer insulation (eg: Polyolefin or Polyethylene)
that meets SAE J-1128.
This stuff has a temperature range of -51ºC to 125ºC +
(-60ºF to 257ºF +). The main advantage of cross-linked polymer
is that it resists 'plastic flow'. Just having it bend around a chassis
member isn't going to result in an exposed wire in the future.
There are at least three grades: TXL, GXL and SXL. The difference
between these is in the insulation wall thickness. TXL is the thinnest
of these, SXL is the thickest.
Painless Wiring sells TXL in bulk. With their wire, you have a very
thorough selection of gauges and colours - replicating a factory
harness right down to the colour coding is straightforward.
and need to create your own wiring harnesses.
Be aware that the conventional automotive wire available from
jobbers is marked as GPT (General Purpose Thermoplastic). It is
typically good for only -10°C to +105°C. This just won't be sufficient
for underhood conditions. Maybe worse is that its Polyvinyl
Chloride (PVC) insulation will flow away from a load, this means
that it can eventually expose bare wire at points where it passes
through a bulkhead or is zip-tied to something.
For your wiring, consider hunting down conductors (wire) with
cross-linked polymer insulation (eg: Polyolefin or Polyethylene)
that meets SAE J-1128.
This stuff has a temperature range of -51ºC to 125ºC +
(-60ºF to 257ºF +). The main advantage of cross-linked polymer
is that it resists 'plastic flow'. Just having it bend around a chassis
member isn't going to result in an exposed wire in the future.
There are at least three grades: TXL, GXL and SXL. The difference
between these is in the insulation wall thickness. TXL is the thinnest
of these, SXL is the thickest.
Painless Wiring sells TXL in bulk. With their wire, you have a very
thorough selection of gauges and colours - replicating a factory
harness right down to the colour coding is straightforward.
TXL: -51ºC to +125ºC => -60°F to +257°F
In a simple test, a piece of GPT wire was brought close to the
flame of a propane torch. At some distance from the outer cone
the GPT insulation quickly softened and began to flow, exposing
the bare conductor. In contrast, a piece of TXL wire was able
to be positioned into the cone of the flame and held there - the
insulation on the exposed side charred and blistered but did not
expose the inner conductor.
The TXL wire used above was from bulk wire distributed by Painless.
However, you can reproduce the test for yourself if you happen to
have an in-line fuse with the thick orange insulation such as these
ones available from NAPA.
These f-holders have either the GXL or SXL version (wall thickness?)
of cross-linked insulation. Hold a piece of this up to the flame and
compare the results with what happens to conventional GPT wire,
then decide which is most suitable for your application ...
.
