Pennock's Fiero Forum
  Technical Discussion & Questions
  What gauge of wire should i buy?

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
What gauge of wire should i buy? by fisherlr777
Started on: 11-19-2013 09:33 PM
Replies: 20 (495 views)
Last post by: phonedawgz on 11-23-2013 06:18 PM
fisherlr777
Member
Posts: 29
From: Kearney, NE
Registered: Sep 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-19-2013 09:33 PM Click Here to See the Profile for fisherlr777Click Here to Email fisherlr777Send a Private Message to fisherlr777Edit/Delete MessageReply w/QuoteDirect Link to This Post
The smallest wire my hardware sells is 14-gauge. Which is clearly too large, i'm not sure exactly which gauge i should be using, or what kinda jacket the wire needs. Any help?
IP: Logged
PFF
System Bot
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 307
Rate this member

Report this Post11-19-2013 10:26 PM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
The size of the wire depends on what size fuse protects the circuit. What are you installing the wire for, and are you planning to splice it into an existing circuit or are you planning to install a dedicated fuse for it?
IP: Logged
fisherlr777
Member
Posts: 29
From: Kearney, NE
Registered: Sep 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-19-2013 10:36 PM Click Here to See the Profile for fisherlr777Click Here to Email fisherlr777Send a Private Message to fisherlr777Edit/Delete MessageReply w/QuoteDirect Link to This Post
Wiring a full 3800 harness up to the c203,c500,BCM and engine. All the wire seems to be the same gauge to me, but i'm not an expert. I plan to pull every pin and resolder every wire or buy new pins/terminals where necessary.

IP: Logged
Bloozberry
Member
Posts: 7760
From:
Registered: Jan 2009


Feedback score: N/A
Leave feedback





Total ratings: 307
Rate this member

Report this Post11-20-2013 07:57 AM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you're building your own harness, then you really should get a manual which shows you the size of the wires used in the stock configuration. While some people use just any old wire they can come across, the gauge of the wire is chosen to support the amount of electrical current (amperage) of the total current draw on any given branch of a circuit. If you over-size the wire, there aren't any problems except that it's harder to work with and can add more than a few pounds to your car. If you under-size the wire, you risk melting the insulation and having shorts and even fires.

Here's an example of a typical wire diagram:



The number just before the color of the wire (for example "1 ORN" at the top) indicates the gauge of the wire that's used in metric. A 1.0 is equivalent to 16 AWG. All of the wire diagrams show several different wire gauges throughout. You can't always judge the gauge of the wire by looking at it's outside diameter since different insulation materials and thicknesses are often used. If it helps, here is a conversion chart from metric to AWG sizes:

Metric / AWG

0.22 / 24
0.35 / 22
0.5 / 20
0.8 / 18
1.0 / 16
2.0 / 14
3.0 / 12
5.0 / 10
8.0 / 8
13.0 / 6
19.0 / 4
32.0 / 2

IP: Logged
HarryG
Member
Posts: 587
From: Central Ohio, USA
Registered: Sep 99


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-20-2013 11:10 AM Click Here to See the Profile for HarryGClick Here to Email HarryGSend a Private Message to HarryGEdit/Delete MessageReply w/QuoteDirect Link to This Post
If I were you, I'd switch from the hardware store to an autoparts store for wire in small lots. My local NAPA carries some sizes, but it would be pricey if you had to make long runs.
IP: Logged
thesameguy
Member
Posts: 1414
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-20-2013 01:05 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
FWIW, I buy automotive wire from wiringproducts.com - they have good quality wiring at reasonable prices. If you need a lot, I'd recommend waytekwire.com as they're a pleasure to deal with.

I'll also throw this out: Go to the junkyard with a big ol' bolt cutter and find a couple cars that have had interiors pulled and then chop the harness that runs the length of the car, like down the center tunnel or the sill. You get nice ~6' lengths of wire in lots of pretty colors that you know is automotive grade. Sometimes you can ID cars that have similar runs across the radiator crossmember or down a fender, too. I've made some really nice replacement wiring harnesses this way, like a new fuse box for my '62 Falcon:

IP: Logged
Steven Snyder
Member
Posts: 3310
From: Los Angeles, CA
Registered: Mar 2004


Feedback score: (2)
Leave feedback





Total ratings: 106
Rate this member

Report this Post11-20-2013 04:25 PM Click Here to See the Profile for Steven SnyderClick Here to visit Steven Snyder's HomePageClick Here to Email Steven SnyderSend a Private Message to Steven SnyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Bloozberry:

Here's an example of a typical wire diagram:

...

The number just before the color of the wire (for example "1 ORN" at the top) indicates the gauge of the wire that's used in metric. A 1.0 is equivalent to 16 AWG. All of the wire diagrams show several different wire gauges throughout. You can't always judge the gauge of the wire by looking at it's outside diameter since different insulation materials and thicknesses are often used. If it helps, here is a conversion chart from metric to AWG sizes:



Very useful information! I hadn't realized that the wire gauge was in the diagrams.

 
quote
Originally posted by thesameguy:

FWIW, I buy automotive wire from wiringproducts.com - they have good quality wiring at reasonable prices. If you need a lot, I'd recommend waytekwire.com as they're a pleasure to deal with.

I'll also throw this out: Go to the junkyard with a big ol' bolt cutter and find a couple cars that have had interiors pulled and then chop the harness that runs the length of the car, like down the center tunnel or the sill. You get nice ~6' lengths of wire in lots of pretty colors that you know is automotive grade. Sometimes you can ID cars that have similar runs across the radiator crossmember or down a fender, too. I've made some really nice replacement wiring harnesses this way, like a new fuse box for my '62 Falcon:


That really is the best/cheapest way to get a lot of good wire wire in a variety of jacket colors and stripes, without having to buy a bunch of large rolls. The interior harness tends to be uncorroded and long. Engine harnesses are not good to harvest from, because the wire insulation is usually degraded due to exposure to high temperatures, and the wires can be corroded from the terminals to a few inches down, even under the insulation.

I can also recommend Waytek Wire as a great source. Good customer service, good prices, and a wide selection. Some components are only available in large quantities though.

I found this place recently as well: http://www.genuinedealz.com/ They mainly sell marine wiring stuff, so it's a good source for adhesive-lined heat shrink tubing, bus bars, covered fuse blocks, etc.

[This message has been edited by Steven Snyder (edited 11-20-2013).]

IP: Logged
phonedawgz
Member
Posts: 17009
From: Green Bay, WI USA
Registered: Dec 2009


Feedback score:    (23)
Leave feedback





Total ratings: 290
Rate this member

Report this Post11-20-2013 05:32 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
It is a mistake to use anything but cross-linked polyethylene underhood, especially with a 3800 in a Fiero. Cheap hardware store wire is a fire hazard. PVC automotive wire is less than acceptable.
IP: Logged
thesameguy
Member
Posts: 1414
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-20-2013 06:01 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Steven Snyder:
I found this place recently as well: http://www.genuinedealz.com/ They mainly sell marine wiring stuff, so it's a good source for adhesive-lined heat shrink tubing, bus bars, covered fuse blocks, etc.


Thanks for that! I just bought a big QuickCable battery cable crimper (tired of my "hammer based" crimper fer realz) but the place I bought it from doesn't stock adhesive heat shrink... And, that reminds me - www.remybattery.com has, as you would expect, a lot of battery cable and some miscellaneous wiring supplies, and they're also nice to deal with. Bought the crimper and the QuickCable lugs there.

IP: Logged
theogre
Member
Posts: 29212
From: USA
Registered: Mar 99


Feedback score: N/A
Leave feedback





Total ratings: 549
Rate this member

Report this Post11-20-2013 07:33 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fisherlr777:
The smallest wire my hardware sells is 14-gauge. Which is clearly too large, i'm not sure exactly which gauge i should be using, or what kinda jacket the wire needs. Any help?

Insulation needs higher temp plastic that resist oil etc.
Many "off the self" wire at parts stores and others won't last long in engine bay.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)


The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

IP: Logged
olejoedad
Member
Posts: 14019
From: Clarendon Twp., MI
Registered: May 2004


Feedback score: (5)
Leave feedback





Total ratings: 188
Rate this member

Report this Post11-21-2013 07:34 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
To reiterate and clarify......

The wiring used in the interior of the car is not suitible for the temperature under the hood. Also, the engine harness and the interior harness do not share a lot of the colors/gages.

Go to the wrecking yard and choose about any GM car and chop out the engine wiring harness.

There is absolutely no problem with properly splicing and insulating wires rather than using new wire/pins.

Your approach may be good for saying "My harness is all new", but the finished product will not perform any better than a harness that is constructed from donor underhood harnesses using proper splicing techniques.
IP: Logged
PFF
System Bot
1fast2m4
Member
Posts: 513
From: Frederick, MD (U.S.A)
Registered: Feb 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-21-2013 10:27 PM Click Here to See the Profile for 1fast2m4Send a Private Message to 1fast2m4Edit/Delete MessageReply w/QuoteDirect Link to This Post
Go to your local junk yard, tell them what your doing and ask if you can just buy a few feet of wiring harness. 5-10 min and some bolt cutters and you'll have plenty of super high quality wire. most yards will have a bin full of misc. harness $20 should get you more than enough wire and it will be MUCH better quality than anything form a hardware store and you'll have many different colors .

------------------
1986 SE 3800SC/4t65eHD (12.871@104.96) I'll Sell it if you like
1985 GT 3800SC (swap in progress)

IP: Logged
84fiero123
Member
Posts: 29950
From: farmington, maine usa
Registered: Oct 2004


Feedback score: N/A
Leave feedback





Total ratings: 325
Rate this member

Report this Post11-22-2013 09:00 AM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
Radio Shack sells just about every wire size insulation you could want in rolls so you just need to buy the right colors for the right gauge wires. and there are a few different ones depending as others have said on what is going threw them. your local store might not have all the right ones but they can, or you can get them threw them.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

IP: Logged
thesameguy
Member
Posts: 1414
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-22-2013 01:02 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by olejoedad:The wiring used in the interior of the car is not suitible for the temperature under the hood. Also, the engine harness and the interior harness do not share a lot of the colors/gages.


That is a broad and inaccurate generalization.

IP: Logged
rogergarrison
Member
Posts: 49589
From: A Western Caribbean Island/ Columbus, Ohio
Registered: Apr 99


Feedback score: N/A
Leave feedback





Total ratings: 552
Rate this member

Report this Post11-22-2013 04:58 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
About all that Radio Shack now sells thats usefull is the wire. The interior wiring from a junked car is a good cheap source...just do the yard a favor and dont cut them out of a car with a good floor and rear section. I hated buying a used rear or front clip WITH the wiring included, to find out some azz ripped out all the wires and I had to spend a day or two making up a whole new set for free. I dont know how many times I bought a used door where the wiring connector was cut off with bolt cutters only inches from where it unplugged. Why not just unplug it and save me a day of handwiring a door.
IP: Logged
thesameguy
Member
Posts: 1414
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-22-2013 05:35 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
I've never understood pointless junkyard destruction - if the choice is a couple hours of dismantling or violence, I can understand the quandary, but if it's the same amount of work and one path doesn't screw the next guy, why not be courteous?

Years ago I spent hours taking a transmission out of a car and because I try to be courteous each sub-assembly I removed I put in the trunk, doing my best to contain relevant hardware nearby. The wiring harness was unplugged and coiled up in the back seat. About two weeks later on a forum I frequent someone posted a message saying "Whoever dismantled this junkyard car, thank you" with the details inside. We had a good laugh and two people got to go home happy from the junkyard. Good times.
IP: Logged
olejoedad
Member
Posts: 14019
From: Clarendon Twp., MI
Registered: May 2004


Feedback score: (5)
Leave feedback





Total ratings: 188
Rate this member

Report this Post11-23-2013 08:22 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by thesameguy:


That is a broad and inaccurate generalization.


No, it is not.
You are incorrect.
The answer is specific to the Fiero and other GM car harnesses.
I have built several harnesses for Fiero swaps, as well as harnesses for other vehicles.
The interior wiring insulation is not suitable for use in the engine compartment. It does not have the temperature range neccesary for the environment.
The engine wiring also has several color combinations that do not appear in the interior harnesses.

When building a harness it makes a lot of sense to follow the wiring color codes used by GM. Later troubleshooting is a lot easier when each wire can be recognized by color code.

IP: Logged
rogergarrison
Member
Posts: 49589
From: A Western Caribbean Island/ Columbus, Ohio
Registered: Apr 99


Feedback score: N/A
Leave feedback





Total ratings: 552
Rate this member

Report this Post11-23-2013 03:39 PM Click Here to See the Profile for rogergarrisonClick Here to Email rogergarrisonSend a Private Message to rogergarrisonEdit/Delete MessageReply w/QuoteDirect Link to This Post
To add to your point. There are also different grades of loom. Some are for general electrical, others are heat rated for underhood. Putting interior rated loom under the hood is a bad idea. It melts.
IP: Logged
thesameguy
Member
Posts: 1414
From: California
Registered: Dec 2012


Feedback score: N/A
Leave feedback

Rate this member

Report this Post11-23-2013 04:17 PM Click Here to See the Profile for thesameguyClick Here to Email thesameguySend a Private Message to thesameguyEdit/Delete MessageReply w/QuoteDirect Link to This Post
While it may make sense to use GM wiring for such a project, nowhere in my post did i suggest sourcing the wire from a GM vehicle. I can't say whether it's true that GM uses different wiring underhood than in the passenger compartment, but that is atypical and certainly untrue of every other car I own which, at the moment, comprises eight models from six non-GM brands. It may be true of GM, but it's not true of Saab (pre GM, for clarity), Audi, Jaguar, Ford, Volvo, or Toyota. So, my statement stands that claiming inside wiring is different than underhood wiring is different is an inaccurate generalization. GM practices != all manufacturer practices. I can't even find a single reference to the notion via Google, so I question whether it's true at all. I'd be very interested to know more about this, so any links you can provide would be helpful.
IP: Logged
Gall757
Member
Posts: 10633
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post11-23-2013 05:34 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
IP: Logged
phonedawgz
Member
Posts: 17009
From: Green Bay, WI USA
Registered: Dec 2009


Feedback score:    (23)
Leave feedback





Total ratings: 290
Rate this member

Report this Post11-23-2013 06:18 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageClick Here to Email phonedawgzSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
GM switched to cross linked insulation around 1990. The stuff they used in 80s cars (including the Fiero engine harness) is a lower grade than what you want to run in a 3800 Fiero.
IP: Logged
PFF
System Bot

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock