wiring

[57chevyman]

hey y'all
i know this has been covered, but can you point me in the right direction for complete wiring kits.

my truck has real old wires and im thinking to rewire the truck with a new fuse box and all that stuff. for peace of mind that i know the wiring is good.

i heard of "painless" wiring kits? is that the good stuff?

i need a pretty basic kit. no computer or fuel injection or sensors or ABS..

i have a SBC engine. no AC, but i may do it one day.

[NorCalGal]

I bought the American Autowire kit, its a little pricey but was told it has copper contacts in the fuse box instead of tin. It can be bought with 14-22 circuit.

[OrrieG]

EZ wire 18 circuit should work for you. Light switch, ignition switch, dimmer, horn relay come terminated. Lights and engine do not but I found in most cases you need to shorten the wires and end up doing your own terminals. Good instructions and the two times I needed help the US company owner answered the phone himself and had the answer. All the wires are labeled and color coded closely to stock GM colors.

[OneOffStroker]

Painless is a great kit with very good instructions. EZ Wire is also a good kit, but the instruction manual is not as good as the Painless kit.

You would be fine with a 12-circuit kit if you don't plan to add much of anything to your truck. Also, I would HIGHLY advise that whatever one you choose, get the full size fuse block. I got a 'mini' fuse block for the harness I installed in my '69 Suburban, and I was completely dissatisfied with it. The relays were just terminated onto pigtails and no place to mount, and the cover could easily be installed upside-down, leading to incorrect fuse identification.

Anyway...get a harness and install it, regardless of what brand you go with. It is always the FIRST step in any of my builds, whether it's a classic truck or a motorcycle. Eliminating decades worth of wiring gremlins will lead to a much better motoring experience.

[dwcsr]

I think the major differences are that American is a truck & year specific harness and EZ and Painless are generic universal kits. American has several diagrams in the kit of each harness section. The only bad thing about American is that it will not use the amp gauge, the others I'm not sure about. If your using aftermarket gauges or converted your amp gauge to a volt meter its a non issue.

[_Ogre]

i have to agree with everything above
aaw is truck specific and easiest to install, not very flexible for add-ons and most costly by far

painless and ezwire are most flexible and less costly with plenty of wire length to fit any length vehicle
you do need to save and reuse a lot of connectors or buy new connectors
you can go to the painless tech section and download their instructions to read them
look at the price; if your on a budget you'll go with ezwire like ogre did

if your truck has been converted from a generator to an alternator, bypass or convert the ammeter
i'm not a fan of running a 60 to 100+ amp current thru the 30 ammeter
read how i converted the amp gauge to a volt gauge in my build

[Dan in Pasadena]

Originally Posted by dwcsr

I think the major differences are that American is a truck & year specific harness and EZ and Painless are generic universal kits. American has several diagrams in the kit of each harness section...

Ah.... another nugget of information gleaned from the Internet, thanks!

So...I've never wired a car before and have a few things/thoughts I've gathered from reading every general wiring thread I've found online.

1. Mount the (full sized!) fuse panel first. Usually driver side interior firewall but sometimes driver side under seat, and I've even seen someone(?) mount a pull out panel on a drawer slide under the seat.

2. Divide the wires into those that run toward back of truck, into cab, into engine compartment, and to front of truck - head & signal lights and electric fan wires.

3. Have rock solid grounds from battery to frame, engine to frame and body to frame. I'm also thinking a ground from the bed to frame might be a good idea(?)

4. Each wire for each device is positive (except on positive ground systems) and runs to the device. A ground from each device gets to the body or frame unless of course the device grounds itself through its case.

5. Route the wires along the frame in groups that terminate near each other through loom - but I don't know if the garden variety split plastic loom from your local Autozone or PepBoys is fine...or crap? If crap, what to use?

5A. In my case, I don't want wires to show in the engine compartment so I plan to run the engine compartment wires through a (grommeted) hole very low on the firewall and the wires to the front of the truck through a hole in the driver side kick panel area and along the wheel well area.

6. Back to loom, mount the loom through those plastic coated clamps (I don't know their proper name) screwed to the frame. If you're truly anal I suppose you could resistance weld studs to the frame so there'd be no screw heads visible outside the frame.

7. All terminations using GOOD terminals (Brand? Source?) must be soldered; not just crimped, and covered with heat shrink tubing.

8. ALL holes must have a grommet installed.

QUESTIONS:
What gauge wire to use for the grounds?
I don't understand dielectric grease. For grounds do you put it between the ground wire and frame then screw the termination down? Or do you screw the termination to the frame and THEN coat the connection in dielectric grease?
I also don't understand primary vs. secondary engine wring but I assume the kits that have better instructions (which ones?) make it clear what to do.
Better to use door-to-door-frame contacts? Or pass wiring from door frame to door through some kind of flexible conduit?

[dwcsr]

Soldering isn't a must unless its a high vibration device your connecting to such as in off road or rock crawling. A good crimp and a heat shrink is fine. Primary is 12 v electrical circuit, secondary is the ignition high volt such as spark plug wires, coil and the like. If you use a door contact your windows, poppers and locks won't work when the door is open, may be not an issue, if you use flex conduits pre plan that at the time of the metal repair, in some truck its major surgery to place them.

6 or 8 on the body ground should be enough. engine to frame and engine to battery should be heavier and make sure they are very good, you don't want your starter circuit grounding through the cab when the battery ground is bad. I've seen instances where the starter circuit actually grounded through the choke cable, the whole outer jacket turned bright read when starting.

[57chevyman]

Thank you for the info! heres a pic of what i have now... pretty sad looking. but every single thing electrical on the truck works. every bulb, every directional, horn, wipers, radio, heater fan, 12v outlet.. you get the picture.. it all works.... but that little fuse box has no constant "ignition off" power... so i had to run wires with inline fuses direct to the battery to get the dome light to work, and to install the radio

[OrrieG]

Dan some comments. Ground, I used 12g from individual devices, if required. I used the original strap ground to cab. #4 battery cable ground from engine to ground bolt, frame to ground bolt, front clip to ground bolt (headlights and turnsignals), and bed to frame at back (tail, back up lights and hitch wiring ground).

The split corrugated loom is a pain to keep clean especially on a driver. The spiral I used for short terminations. For main looms I used an oil, gas and fire resistant woven product (see photo).

For terminations go to an automotive electrical jobber and buy PICO or similar connectors. I crimped all of mine. I saw a show on TV about off road rally car construction, they use aircraft rated connectors and crimps. The interviewer ask about soldering, they said the vibration cause breaks where the solder ended. Looks like you have everything else covered.

[Coupeguy2001]

That wiring looks beautiful!
you should have seen mine when I got it. Somebody cut every wire, then twisted them all back together. Then they used rubber bands to keep the bare wire from touching metal.
Nothing wrong with that little fuse panel except it got painted. Put some new fuses in it and clean off the terminals until you are ready to strip every wire out of the truck.

I bought a new wiring harness from a truck parts place in Moreno valley, AZ, that was duplicated from an original harness. Nothing but the factory basics. They used the new type wire, and every wire has a number on it at both ends and every 6 inches.

Twenty years later, I have added a bank of relays and fuse panel to fuse everything.
I remember installing the wiring harness and noting that the turn signals were a secondary harness complementing the main harness, then read somewhere that the turn signals were an option, and the extra harness was laid over the main and terminated.

So I figure, if I kept it neat, I could do the same thing with all the other things I added, and it looks good.

BTW, I am an aircraft mechanic, and there is a big difference in terminals and splices between automotive and aircraft.
The biggest difference is that aircraft copper terminals is alloyed with metals that increase it's strength.
If you have ever straightened a terminal by pulling on the wire, with an aircraft terminal, you need to use duckbills.
(don't pull on wires anyway).
Also, the aircraft terminals don't seem to break with vibration so much either.
The insulation is a hardened plastic of some type that resists abrasion as well.

There is a company named AMP that manufacturers a lot of the aircraft stuff, and it is pricey. You might be able to find the terminals on eBay where they claim it is amp stuff pretty cheap.
all of my stuff is amp. I even bought the amp crimpers at a aircraft surplus tool outlet.

I just wished I'd slowed down enough to make better wiring diagrams.

I also bought a fuse panel, out of a 2007 chevy Malibu and all the wiring. it cost me $50.
But that fuse panel has markings and fuses for everything in newer cars. like fuel pump, daylight driving lights, instruments, current limiters for cigarette lighters to run accessories, relay sockets, etc.
GM dealers sell the terminals to crimp your own wires to make them custom lengths and run them where you please.
I would guess about $40 for a few bags of terminals to fit the fuse box and about $45- $55 for wire.
$50, +$40,+ $55

[Dan in Pasadena]

Originally Posted by dwcsr

Soldering isn't a must unless its a high vibration device your connecting to such as in off road or rock crawling. A good crimp and a heat shrink is fine.

This is excellent info. I suppose I just assumed solder was required because everyone that did it seemed to brag on it.

Originally Posted by dwcsr

Primary is 12 v electrical circuit, secondary is the ignition high volt such as spark plug wires, coil and the like.

Yeah, I knew that so I miscommunicated. I think what I'm saying is I feel clueless about how the ignition circuit works.

Originally Posted by dwcsr

6 or 8 on the body ground should be enough. engine to frame and engine to battery should be heavier and make sure they are very good, you don't want your starter circuit grounding through the cab when the battery ground is bad. I've seen instances where the starter circuit actually grounded through the choke cable, the whole outer jacket turned bright read when starting.

Good info, excellent advisory on the ground. I didn't know that was possible! Yikes!

[1958Warrior]

I ran across this last night wile ordering a DD steering shaft off ebay decent at $70+free ship:

http://www.ebay.com/itm/18-CIRCUIT-U...item23578d6f0c

I bought a EZ wire harness a while back it is a 21 circuit kit, its a large fuse box, I haven't installed it yet, but wondering if I need that many fuses, my truck will be pretty basic also engine , lights and a radio, but with electric fuel pump and elect. fans , and AC someday ,so I went bigger.

[57chevyman]

Originally Posted by Coupeguy2001

Nothing wrong with that little fuse panel except it got painted. Put some new fuses in it and clean off the terminals until you are ready to strip every wire out of the truck.

i think ill just leave it alone...been the way it is for over 10 years .
looks like a i have 5 fuses. all of em are 30.

the kit on ebay thats $70 looks nice, but am i better off playing extra for ezwire or painless?

[57chevyman]

Originally Posted by 1958Warrior

I ran across this last night wile ordering a DD steering shaft off ebay decent at $70+free ship:

http://www.ebay.com/itm/18-CIRCUIT-U...item23578d6f0c

I bought a EZ wire harness a while back it is a 21 circuit kit, its a large fuse box, I haven't installed it yet, but wondering if I need that many fuses, my truck will be pretty basic also engine , lights and a radio, but with electric fuel pump and elect. fans , and AC someday ,so I went bigger.

actually , that kit on ebay looks a little cheap. i like how the ez wire fuse boxes are labeled... the 12 circuit one is just about the same price as the 21 circuit...difference is $10

being that the 12 circuit one is twice the circuits as i have now, i probably makes sense to go with that one?
on the other hand, i see things in the larger fuse box that i have... dome light, cigg lighter, that arent on the smaller fuse box? i assume that my small 6 circuit fuse panel i have now has multiple things combined on each circuit and thats why the fuses i have are all 30s. guess the 21 circuit one here is the one to get? advise me

[Dan in Pasadena]

If it were me - and it will be in awhile - I'd buy MORE capacity, not less. Particularly for only $10. But I'm also one who needs super complete instructions and diagrams/photos.

I'd probably pay a little more for better instructions, but that's just me.

[Iceburgh]

I have used them all over the years. Haywire is the best for my money

[Coupeguy2001]

As long as the wire conforms to SAE GXL or SXL standards, the fuse boxes should be equally trouble free.
Most of the contacts are brass for strength and heat and corrosion tolerance.
newer cars have stainless contacts in high amperage circuits.

If you are concerned for your vehicle, every manufacturer has a "contact us" link on their website.
Usually you can ask about quality issues and standards and they will reply without obligation to buy.

If you go to a hardware store, in the area where they sell SAE bolts and automotive things, there is usually connectors, wire and contacts for sale.
Just watch what you buy, there are larger contacts and smaller contacts for your wiring projects. The larger ones don't fit in the GM plastic connectors (spade type).

GM weatherpak connectors are sold with their contacts, and need special crimpers.
Usually, you can buy GM weatherpak connectors at swap meets and car/hobby shows. I finally found a throttle position sensor connector at a swap meet here in Phoenix, and the guy was selling them for $2.50. Cheap when you realize GM gets $25 for the same thing.


The contacts and connectors and relays sold at autozone and O Reilly's are adequate for the amp rating they are advertised for.
If you are adding a single circuit, Just don't buy a fuse holder that is sold with a 15 amp fuse and replace it with a 20, 30, or 35 amp fuse. The reason is that the wire isn't rated for that much current. The wire will overheat, and melt the fuse holder, and the wires can touch and short out, making the fuse worthless, and possibly cause a fire.
Buy a fuse holder with the size of fuse that you need for your circuit.

If you buy a fuse box with wires already on it, pay attention to the wire size. If you have a headlights slot for example, and it is a 5 amp fuse, it is sized to operate the headlight relay, and not run the headlights. The original headlight switches in our trucks were made to carry heavy current, and using a headlight relay may make them brighter.

Relays are your friend. Use as many as you can. They are basically an electrically operated switch that places the heavy amps out of the passenger compartment, and puts the relay panel and heavy gauge wires under the hood.
Car manufacturers use senders and sensors to eliminate putting flammable fluids and ignition sources inside the car, like fuel pressure, oil pressure, and the use volts instead of ammeters. If you burn up a volt meter wire, nothing happens because the wire will burn through and stop conducting. A heavier wire may get hot enough to overheat the entire wire harness and start a fire.
As it's nice to know how many amps your particular circuit is drawing, the volt meter is also a good indicator of what's going on as well, and the wires can be a s small as 20 ga wire, and still display the volts.
For instance, If a car uses an ammeter, a 20 amp circuit wire might be 12 or 14 gauge if it runs a fuel pump under the trunk. If there are several that size, the wire bundle could be over an inch in diameter.
The voltmeter uses much smaller wires, and rely on the fuses to indicate when the amp draw is excessive by burning up, so the bundle of wires inside the car are fewer and smaller.

For instance,
go out to your car that has a voltmeter, and turn on the ignition without starting the car. if it reads about 13-13.5 volts, it means your battery will probably start your car.
If you start the car, and the volt meter rises almost immediately to 14-14.5, it means that the alternator is good, and charging a good battery.
If your volt meter starts out at 11-12 volts, and your starter drags a little, it may indicate a weak or bad cell in the battery, or a weak alternator. When it is started, and the meter takes a couple minutes to get to the 14 volt range, it could mean the belt is slipping, the alternator is weak, dirty battery cables, or your battery is weak, needing a longer charge to get it up to the expected operating range.
There are hundreds of electrical issues that can occur.
In any case, the voltmeter is a handy tool.
Wiring can be fun, and be sure to draw a diagram on a separate sheet of paper for each circuit. That way, when you are done wiring up your truck, you can have a great reference when something fails to operate. and like Factory manuals, you can use one side of the paper to add notes, like :
headlight relay located under right hand cowl, or behind glove box, etc.
That way, later, you will jog your memory with your notes.
When it comes to electrical, use best practices.

Remember, car makers these days have dozens of electrical engineers dreaming up what once was an exotic circuit, and designing the circuits to last 20 years.
Reliability Reliability Reliability.

um, that's probably a lot more than I really thought about saying.
Anyway, you get the picture.

[2tractors]

Soldering requires anti wicking tools to prevent the flux inside the solder from wicking up inside the wire insulation. Once that happens it's just a matter of time till the wire becomes brittle and either breaks or turns into a cold solder joint. I'd stick with crimps.

[_Ogre]

i think ill just leave it alone...been the way it is for over 10 years .
looks like a i have 5 fuses. all of em are 30.

i can understand not wanting to rewire the whole truck when everything works fine

but... 5 - 30 amp fuses going to everything isn't protecting any wiring in your truck
a 25 amp overload under the dash may burn your truck to the ground without popping a fuse
that's akin to wrapping aluminum foil on the old barrel fuses

if your truck is basically stock a few 15 amp fuses are all you need
originally the tf trucks had no fuse panel; one fuse on the headlight switch for the dash lights
the factory headlight switch has auto-reset overloads built in the switch to protect the wiring and leave you with lights
even the fully optioned trucks with turn signals, heater, electric wipers, radio and cig lighter only had 4 or 5 fuses

do not connect the headlights to a one time fuse otherwise you may find yourself running down a mountain road sans headlights
at a minimum replace all those fuses with 15 amp and wire the headlights straight to the main hot wire

[1project2many]

that's akin to wrapping aluminum foil on the old barrel fuses

I'm sorry, but 25A fuse < 1,000,000A foilfuse.

[YukonXL04]

Originally Posted by _Ogre

that's akin to wrapping aluminum foil on the old barrel fuses

HAHA My 50 came with one of those!! I still need to investigate why they did that.

[straps57]

I used these NSPA crimp/solder/heatshrink connectors on my radio install recently and loved them. Wound up finding them on Ebay because everywhere else was really expensive.

https://www.youtube.com/watch?v=Skf3mkwW20Y

[OrrieG]

Originally Posted by YukonXL04

HAHA My 50 came with one of those!! I still need to investigate why they did that.

That is why you always find old chewing gum wrappers in the cab corners....

[Dan in Pasadena]

Originally Posted by straps57

I used these NSPA crimp/solder/heatshrink connectors on my radio install recently and loved them. Wound up finding them on Ebay because everywhere else was really expensive.

https://www.youtube.com/watch?v=Skf3mkwW20Y

I very cool, but necessary per dwcsr, above?