Wiring harnesses

[TonyMadrid]

Another question for the gurus.

How difficult is it to make a wiring harness rather than buy one?

The prices I'm seeing for harnesses seem pretty high to me; especially when all they are made of is various gauges of wire, bound with black electrical tape and fitted with appropriate terminal ends.

Has anyone out there made his own and was it difficult?

Any tips would be appreciated.

Tony

[trularin]

It all depends on your ability and knowledge of electrical.

Personally i wire my own. I use better than factory and add features as I want them.

I did not do it because of the money.

If you have acess to automotive electrical, and you know what you are doing, go for it.

However, if you put a wire that is too small for a unit that requires a large current, you can go up in flames.

Hope this helps.

Trularin

[Thomas Gayer]

i did it for the money
i spent less than $100
have tons of wire and connectors left over.

be sure to use the 4foot $16 1.5 ohm NAPA resistor wire going to the plus side of the coil or you will burn up your coil or car

good luck
tommy

[Bob Putnam]

Tony,

Our 427 harness contains over thirty different wire color/gages, more than twenty different wire terminations and takes about 10 hours to fabricate on several wiring boards - when done in runs of 5 to 10.

More power to Tommy for his frugality, but I suspect he uses only a couple of colors or gets his wire for free.

How much is your time worth? Figure on spending 15-20 hours on your first harness.
If you know what you're doing...

[Thomas Gayer]

please , give me a break
you can see the some of the different wire colors i used on the dash if you click on my camera next to my name.
i admit doing all the wiring in black only would have been neat but i would hate to trouble shoot it later.
i bought my wire at home depot

time is what the $500 harness is worth,
but you are stuck with where they want you to put your instruments and fuses, etc.

i have a 78 mustang column and wanted my tach on the left and the speedo on the right. my cd player and cigarette lighter below the five instruments with the ignition to the left of the bottom gauge. i am putting all fuses etc under the dash not to clutter up the engine bay when i pressure wash it as my cobra will be an everyday driver.
time is money, that is your decision
i redid a 78 mustang II front end with polyurethane bushings etc, but in retrospect when i build my gt40 i will use a new wishbone front end, due to the time element.
tommy

[TonyMadrid]

Thanks Guys,

I appreciate the responses and I welcome more. In 1979 I restored a '57 MGA and I redid the wiring harness myself. It was not that difficult and I agree with many of you that the best route to doing your own harness is to be sure to color-code (use different colored wires) to ease any future troubleshooting issues.

However, I am upset at the prices that I am seeing especially when it is obvious to me that the cost of the materials relative to the prices of completed harnesses is way out of kilter. I would pay more for a knitted sweater because I don't know a damn thing about knirtting. But for harnesses, let's face itr there nothing to gathering and taping wires. In fact, if you wire first, allowing excess, you can place your components anywhere and then just tape and shroud it. Whe it comes to a harness I am looking at it as a challenge in the course of my build.

Hey, but you guys know how this Cobra Build Thing goes; who knows? someone may come across with a great price on a pre-fabbed harness and there goes the need to buy a lot of black vinyl electrical [tape].

Again, I appreciate the replies and I will let everyone know what develops.

P.S. I attended an Automotive HS and worked in the trade years ago for American Motors. Tonight, I came across some wiring diagram notes that I drew when I was in HS, and at 53 yrs old they seem like they were some sort of an accomplishment. If I can get my son to scan them I will post them as pics. Really basic stuff!

Tony

[petek]

I used a Painless kit on my Cobra but on my M6GT I designed my own wiring. While I'll admit that I did some major overkill on the M6GT, the cost of buying all of the proper wire, wire ends, fuse box, and relays exceeded the cost of the Painless kit.

A Cobra is pretty darn simple to wire. No electric locks, no electric windows, no rear defroster, and so on. Do some quick internet searches and you'll find suggested wire gauges for darn near everything in the car. Heck, there is even standard wire colors for a lot of the stuff.

There are ways of keeping the cost down, using one wire color is one way. Using only one gauge of wire is NOT a good way to keep costs down (unless you use 8 awg for everything).

Just don't go out to Radio Shack and figure you'll be able to buy all of the wire you need! Oh, and watch the wire insulation. There are particular types of insulation that work better for cars (where the wire is often subject to temperature extremes as well as vibration and rubbing).

I could probably wire up a car using just 22 awg Radio Shack speaker wire ... but boy would it be ugly as sin!

Go with a Painless (or other) kit.

[Thomas Gayer]

wire size was one of my concerns with the harness.
i wanted to run #6 from my alternator to the starter solenoid as i plan to have a major stereo in the trunk and i didn't feel the #10 could handle it. i would advise against running any wire gauge too small. there are a couple of good wire gauge indicators on the internet.

tommy
got my TCC blanket yesterday
awesome dudes thanks!

[smokintires]

Tony: I bought a harness from EZ Wire - 12 Circuits-11 Fuses * Horn relay & connector *Turn & hazard signals *Dimmer switch connector *Circuit breaker for headlights *2 Flashers *1 Alternator plug *2 Ignition switch connectors *Fuse panel pre-wired *1 Grommet *8 yellow splice connectors *6 Blue splice connectors *6 Small blue lugs *5 Medium yellow lugs *2 Large lugs (one with fusible link) *Small tie wraps *Wires labeled every 5 inches (all black wires). $165. Colored wires cost $160. The directions were not the best, but as mentioned in other posts, these cars are pretty simple. Wire gauges are the same as the expensive harnesses. ezwiring.com/12_circuit_harness.htm

[petek]

Oh, and always remember and ever forget: any wire cut to length will be too short!

[xlr8or]

I have installed Painless harnesses in 3 different cars and they all worked great. Yes it was about $300 per harness but when I looked at the fact that I could go in and completely gut the old harness without worry and then follow some pretty straight forward directions to finish I was very pleased.
The second and third harness took less than a day each to install start to finish. That included removing the old one first as these were restorations. Why bother putting that much time into shopping for parts and pieces when you can have it done in a day? I've never had a problem with any of those harnesses that I installed.

[trularin]

I have found that prewired harnesses very seldon have what I want.

With the number of suggestions from this forum, I would be comfortable with wiring my own. I coulde always ask if stuck.

I like the idea of running #6 over #10 for the alternator wire for added delivery and protection. Good suggestion Thomas.

Tony, Good luck in what you decide to do. When you get stuck with something, ask.

One more thing, if someone told you size doesn't matter, they are wrong.

[Thomas Gayer]

There you go!
smokin tires has the perfect solution for you.
just add a circuit for your cell phone and 7" DVD screen and you're off and running.
tommy