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NEW wiring harness

4K views 27 replies 10 participants last post by  Thom71GT 
#1 ·
I am about to totally rewire my car (71 GT) I am going to make a new wiring harness from scratch. I will Solder all the connections and label all of them to where they need to connect.

I am going to make several of these harnesses and I was wondering who might be interested in buying one and what you thought that would be worth?

A WHOLE new harness on Parsget is close to $800, but that includes a rebuild of your existing fuse box.

Throw me some numbers and dont worry about offending me with low numbers, I know most of us are on a budget. If there is enough interest, I'll build them to order. Otherwise, I'll build 1 or 2 extras and throw them on ebay.

Thom
 
#2 ·
Hey Thom, I was told from some friends who are rewireing a 67 Studebaker that they got a wire kit for about $80 from "E-Z Wire" that includes a new fuse box, but no wire ends. Another company, "Painless" sells a complete set for about $150 to $200. Have you checked out either one?
 
#3 ·
Yes, as a matter of fact I have, but those are generic kits for hot rods and arent specific to the Opel. I want something that is "plug & play" right into the Opel so there is no guessing as to what goes where.
 
#4 ·
Thom,

Have you given any thought to some of the after market modifications, many suggested here, that could be wired in on the first go round.

The few that come to mind real quick are: Headlight relays; Electric fuel pump; Starter switch relay; Single wire alternator; etc?

That's just a few real quickly.

I, too, have been looking to build a harness up. I have been slowly amassing a collection of the various harness pieces to replicate the entire thing (mess).

Good luck!

Chris
 
#5 ·
Yeah, it is a mess. I already have a starter switch that I wired about 16 years ago but havent thought too much about other things. My electronic Ignition that I bought last week should arrive today.

I have a harness for the guages that I bought on ebay and I just bought a FULL harness out of a 72 Gt on ebay but I have yet to hear from the guy on how he wants his payment.

Anyway, I have the nice big wiring diagram and last night I took the harness from behind the dash (for the guages and switches and such) and started writing down the color and guage of wire that I need. I went to home depot but only got some of the wire. Mostly just the 12G and 14G in solid colors. I have some ideas on where I can get the weird striped colors but havent found it yet. I guess it doesnt matter what color the sheath is, but it would make it easier for identification. I bought some labels that I can use too, which Im sure I will.

I've sent a messabe to Painless Performance on a fuse box I can use. Or I might just keep the original in there. I'll let you know how I progress.
 
#6 ·
Thom, et.al., When you take the harness apart here's a thing I did. The wires that are in the gray tubing have not been attacked by UV and have very bright colors. Use these wires at the ends of you solid colored wires and you'll have a very close approximation of the original harness where the wires connect at each end. The solid wires of course will be hiding under the wrap. I used solder type butt connectors from RadShak, but it will take a high wattage soldering gun to make them work. A small iron just doesn't get the connectors hot enough to melt the solder, also I got a solder helper, that will hold the wires via small alligator clips on pivoting shafts that made a lot of the work easy. For my fuse box (circuit breaker/power panel), I used a RadShak 8 X 6 X 3" project box. The original fuse block can be removed from the fuse panel and inserted in the project box and a couple pieces of sheet metal will put the box in the original location. HTH.

Ron
 
#9 ·
There was a post here or on another Opel site where someone gave a location to purchase the wire in the orignal color scheme.

I was also thinking of taking a trip to the local Electrical supply store. Radio Shack only carries minimal electrical goodies. They have gotten away from the home electrical jobber and more into the average end user goodies, such as cell phones and toys...

Anyway, most of the serious electrical supplies can be had at some of the large supply companies. The only problem is, you need to buy the wire in such a large quantity that it becomes quickly cost prohibitive.

JJ may have a supplier that can help you with the colored wires.
 
#10 ·
If you search for harness wires you will see that I posted prices for solid and striped wires from Simcona Electronics. If I remember correctly, the price was the same for 2 and 3 color wires and you could get any combination you wanted. I don't recall the details from Simcona with regards to the wires being gas & oil resistant.

bill
 
#13 ·
Voodoou,

As I'm taking down my '72 it's apparent that I'm going to need a new harness. So are you still thinking about fabricating extras? If your examples are going to be complete with lables and connectors I think the value would be in the $400-$600 range.

I've noticed that the wiring into the engine compartment seems to be much worse than that which goes to the rear. Are those seperate under the dash? I guess I'll find out soon anyway when I pull the dash.
 
#14 ·
The GT's wiring is actually made of of several different harnesses that then connect to the fuse box under the dash.

I just finished buying all the wire that I needed to start the "behind the dash" harness. I'm going to build them one harness at a time.

Since it is difficult to find the EXACT color striped wiring, they HAVE to be labeled or it would be just too much of a pain.

Let me know which one you need and we can agree on a price. If you need the whole thing, then thats fine too.

Thom
 
#15 ·
Go the junk yard and pull all the wiring out of cars that have their interiors already removed: like Volvos, Audis, Porsches, and
VWs (not the bug, too few wires).

I have a huge box of these wires pulled from these cars because you can get Black/green wires and many combos inbetween.

As Ron is doing, I also am doing a severe wiring upgrade to Opel4. (10) wire colors can only go so far; hence the need for Main color / tracer color wires. Most auto wreckers just give me the wire. Convince them that it is not a "harness" but scrap wire you've pulled. If he does not give it to you, give it back; who the hell is going to 'buy' it any way.

Pull the plugs and sockets too; they are reusable and make for very professional, automotive-looking connections . Digikey sells the brass tabs (pins and sockets) But you can reuse the existing brass or copper pins and sockets by soldering to them.
 
#17 ·
That's very true. J. J. Wheatley of DESTEC engineering recommends putting a 25 amp fuse on the yellow/white wire between the headlight dimmer and headlight relay, as a note on his schematic. If you have a GT and don't have J. J.'s schematic, get one. It is a piece of art, one large plastic coated sheet, and you don't need a magnifying glass to read it. HTH.

Ron
 
#18 ·
Wiring Harness

Wow Namba209-that project box was such a good idea- I went to Radio Shack and bought one last night. It is a perfect size-especially for we-wiring. Does anyone know a good source for automotive wire ends. I'd like some without insulation for soldering and crimping like the factory used. Any good source for a kit, and crimping tool?
Keith
 
#19 ·
ive had a hard time finding the disconnects without insulation so Im just going to use the ones with them. The disconnects that are hard to find are the "flag" style or ones that bend at a 90 degree angle. However I found this place on-line

http://www.kayjayco.com/

They are they only place that I have found them and they are fairly expensive at .65 each. I bought 50 of them for $40 including shipping.

I recommend one of those "quick Strip" thingys you see on TV to strip the wires very quickly and easily. I have an extra one if anyone is interested in buying it from me.
 
#22 ·
New Wiring Harness

Been giving it serious thought here lately, Athough I really like Namba's idea of the project box-which I bought one....and the idea of replacing every wire in the GT sounds like a good plan; but is it really necessary to replace all the wiring. Just the fuse box is a spider web of mess, and I don't see a good way of cleaning it up nicely. Can the original style relays be had? Some of the wiring doesn't look bad, and looks difficult to obtain. Should just certain parts of the harness be replaced? I of course would want new engine wiring, but don't see wanting to make a harness for behind the instrument cluster-very nice and compact already. What are some opinions and stories of rewiring? I plan on using OEM Flag style terminals for a professional look.
Keith
 
#23 ·
Keith, what I did for my harness integration for the V-6 mod was check every wire both physically and with a VOM. If it looked suspect it was replaced with a solid color wire, but the original wire was soldered in at each end so it looked original. I haven't totally finished the wiring as of yet, I want to remove the engine/tranny again and reroute the engine/computer harness to get it looking cleaner and closer to the driver's side of the car. All the relays are positioned around the side and rear of the project boxes, I had to use two, piggy-backed for all the circuit breakers I needed for the engine and the original 7 for the car, and 6 Bosch type relays for all the periphals. I used 10-32 stainless allen head bolts, nuts and washers to place all the relays on the boxes. I put a washer and nut on the bolts to hold them to the box and another nut and washer to fasten the relays to the bolts. That way I wouldn't have to open the box if I had to replace a relay. Long winded but I hope this explains what I did.

Ron
 
#24 ·
Hey Namba,

What did you use for the fuse connectors? Now that I have an entire GT harness, including the fuse box to work with, I see how that project box was perfect for this. I just dont know what to use for the connectors and where the fuses go.
 
#25 ·
Thom, I replaced all my fuses with and added 11 aircraft type circuit breakers. I originally had tried to use male/female piggy back terminals, but they were too soft and with the constant movement of the wires, some of them broke. My fix, because I redid the whole ball of wax, was to use two terminal stips from RadShak. I had to use shorting clips to make all the connections from the various circuit breakers when there were more than 4 wires to a circuit. J. J. wheatley has identified a source and page number of the supplier he has used in the past. It's a couple of posts up in this thread. HTH.

Ron
 
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