Ripping out the old wiring harness...

[chester rides again]

I don't think I've posted here in quite a few years. Hell, I haven't driven my '68 109 in the last year, other than around the block a few times. I've just been to busy with work, kids, and life in general.

All that crap aside, I am sick of my electrical system not functioning properly. 2 years ago, I took the truck to a local mechanic to help me get it past inspection as the turn signals, brake lights, wipers and probably something else wouldn't work. He managed to do something so it got past inspection, but the next day, my wiper and turn signals went out again.

I now want to drive this truck on a more regular basis as I'm working 3 miles from home and my life is showing hints of returning to normal... well, close to what i might call normal.

After opening up the instrument panel and staring at the mess of cloth coated, electrical taped and randomly colored PO wires I opened the hood only to find a crud coated wiring loom, a relay floating in mid-air, and more random wires. I've now hit upon the point that the easiest thing for me to do would be to rip all the electrical wiring out and install an aftermarket wiring harness with a suitable number of circuits and properly labeled wires.

I didn't find too many posts on this subject but there seems to be a few companies that are popping up:
1) Painless Performance - looks more expensive than others
2)EZ Wiring - nothing special
3) Kwik Wiring - good $, American made
4) Keep It Clean - again, nothing special - another forum mentioned cheap fuse panel
... I'm sure there are many more.

Anyway, I'm leaning towards Kwik Wiring, but I can't find anyone who's put one of their Universal 14 circuit budget wiring harnesses in a series Land Rover. From what I'm reading, most of these kits allow you to just rip all the wiring out, layout their wiring, attach connectors and ....wait for it.... enjoy driving. The new harness will have each circuit's destination printed on the wires every few inches - bye, bye weird color coding!

Any comments or thoughts?

Jeff

[siii8873]

Hey Jeff,
I've rewired a few rovers, not really that difficult. I'm not far away and could take a look if you want.

I was wondering what happened to you have not seen your rover for quite some time.

[Eric W S]

Our hosts sell the right harness. Or British Wiring. Not that big a deal. My suggestion would be to get a pre made harness that matches the original. Easier to trouble shoot and matches the Green Bible. Once installed, a good oroginal style harness should solve most of your Lucas Gremlins.

[TeriAnn]

I didn't find too many posts on this subject but there seems to be a few companies that are popping up:
1) Painless Performance - looks more expensive than others
2)EZ Wiring - nothing special
3) Kwik Wiring - good $, American made
4) Keep It Clean - again, nothing special - another forum mentioned cheap fuse panel
... I'm sure there are many more.

Any comments or thoughts?

Jeff

You are aware that our hosts sell wiring harnesses.

If you can't find exactly what you are looking for here, try British Wiring. Besides stock wiring harnesses they have harnesses wired for alternators so you don't have to figure out how to bypass the external voltage regulator.

New barrel connectors are very tight. If you are doing a full harness it is worth buying the special tool for making barrel connections and a dab of dielectric grease will help keeping them from oxidizing over time.

I have a wire colour chart that will help you figure which wire goes where.

If you need to add extra wires for any accessories you might have I suggest following the British wire colour standard for the extra wires. You can get striped wires by the foot and crimp on connectors. I suggest getting the proper crimping tool for the connectors.

[chester rides again]

How about wanting to add an improved fuse system? I realize stock would fit perfectly (or at least very close) but i was thinking the extra circuits would be nice for things such as a CB, other lights, and future things...

I have an alternator installed so the stock harness is approaching twice the price of aftermarket...

[o2batsea]

Welcome back.
I bought a BW/Autosparks harness. I ended up cutting all the wrap off it and doing quite a few modifications to it. In my experience, what I would do is order the wire and make the harness myself using the old one, along with the wiring diagram, as a guide.
I'd spend the couple hundred bucks in tools and materials because it isn't difficult to replicate one. having the tools like the bullet crimper and the spade terminal crimper allows you to do future modifications and repairs.
TeriAnn has a nice wiring guide page on her site that gives you the color codes for the wiring. You pretty much need two gauges of green, white, red and black. Then you need the tracer color wires for the stop and turn signals. Oh and a small amount of purple for the dome light.
When I added more stuff like fog lights and seat heaters and heated windscreen and air conditioning and all, I used the wire colors from the Defender electrical manual on RAVE.
BW/Autosparks has all the components you need and the nice thing is they sell wire in meter increments. You don't have to buy huge rolls.
Go with the PVC wrap. Also buy a good rachet type stripper.
I have a nice electrical spares Plano box now with assorted bullets and terminals and vinyl covers and grommets and stuff.

PS re: fuses
The 2A had one fuse in the whole system. That's OK for the standard setup but if you add other circuits, you may want to add more fuses. Especially if you upgrade the headlamps to the Vision Plus type (or take outs from a RRC) They have both old-school Lucas 6 fuse holders, and the new modular mini panels with relay boards mini fuses and it makes adding future components way easier. Not cheap but the stuff is very nice.

[bensdad]

o2batsea,
How would I know which gauges of wire go where? Thanks.

[o2batsea]

o2batsea,
How would I know which gauges of wire go where? Thanks.

Just use the old harness as a guide. Pretty much all the circuit wires use what they call 14 strand which is roughly equal to 18g wire. For the fat brown feed wire to the key switch (and the lights) use 65 strand. When I did stuff like add fused circuits, I used slightly fatter 28 strand wire to the feed side of the fuse holder. So when you order wire, order like 5 meters of 28strand in the main colors of green and white, about 10 of black, and all else you can go with 14 strand. Except of course the brown wire. Get like 5 meters of fat wire for the charge circuit, and 5 meters of 28 strand to feed the fuses.
I won't bore you with how I put solenoids on all my main switched feeds. I also repurposed an old Painless headlight solenoid kit to feed the Hella headlamps.

[rickv100]

Jeff ,

I am in the same situation as I have smoke coming from beneath the dash .

I have an exmod truck and no one makes the harness with the center light switch.

Rick

[rwollschlager]

Welcome back.
I would order the wire and make the harness myself using the old one, along with the wiring diagram, as a guide.
I'd spend the couple hundred bucks in tools and materials because it isn't difficult to replicate one. having the tools like the bullet crimper and the spade terminal crimper allows you to do future modifications and repairs.
TeriAnn has a nice wiring guide page on her site that gives you the color codes for the wiring. You pretty much need two gauges of green, white, red and black. Then you need the tracer color wires for the stop and turn signals. Oh and a small amount of purple for the dome light.
When I added more stuff like fog lights and seat heaters and heated windscreen and air conditioning and all, I used the wire colors from the Defender electrical manual on RAVE.
BW/Autosparks has all the components you need and the nice thing is they sell wire in meter increments. You don't have to buy huge rolls.
Go with the PVC wrap. Also buy a good rachet type stripper.
I have a nice electrical spares Plano box now with assorted bullets and terminals and vinyl covers and grommets and stuff.

PS re: fuses
The 2A had one fuse in the whole system. That's OK for the standard setup but if you add other circuits, you may want to add more fuses. Especially if you upgrade the headlamps to the Vision Plus type (or take outs from a RRC) They have both old-school Lucas 6 fuse holders, and the new modular mini panels with relay boards mini fuses and it makes adding future components way easier. Not cheap but the stuff is very nice.

THIS. I don't agree with Bill often, but everything he said here is on the money!
Stick with stock colour codes, buy the proper ratcheting crimping tools and bullet connectors from British Wiring (also get the bullet connector tool), and you can make your own in short order. I rewired my series III 88 this summer (with a NOS harness) and I found myself glued to TeriAnn's website and the green bible, and discovered the proper wiring tools are worth their weight in gold. By making it yourself you will have a ton of experience (in a good way) and wiring in future accessories in the proper colour code will be child's play. Also, di-electric grease and heat shrink are helpful in most connections as well.

Installation of the hot rod kit only seems easier. "ripping the old one out, laying the new one out, attaching connections" are the three overly-simplified steps for installing any wiring harness. You might as well keep the stock colour code heaven forbid something heads south and you or a future owner needs to fix it.

-Rob

[pjsank]

I have a good deal on a Painless 10104 12 Circuit Pickup Harness with Non GM Keyed Column if you are interested. Sold my 109 before I could start the rewiring project

[TeriAnn]

What you should do depends upon how comfortable you are with reading wiring diagrams and converting them into wiring in your truck.

If the wiring diagram looks like a jumble of lines and you fear getting things wrong and blowing up your truck:

Pay someone else to rewire your truck

If you can mostly understand what the wiring diagram shows you can you know something about electrical circuits:

Purchase a prebuilt wire harness for your year and model of truck and either a generator and alternator. The factory owners manual for your year of truck has the most correct schematic for your vehicle. Lay the harnesses in place and connect them up following the wiring diagram. Test each circuit one at a time, making corrections as needed until all the stock stuff works. In order to minimize inventory makers of prebuilt harnesses will include wires for all the factory options. So don't get excited if you have a few wires that don't seem to connect to anything.

If you want to add a few additional fused wires for accessories you can place a second stock fuse holder next to the other or replace the stock one with a bigger one.

If you put a stock one next to the stock on that came with the harness you can bring the hot wires over from one block to the other then wire up your accessories going through the second fuse block. And remember there is nothing wrong with cutting a wire and adding a single in line fuse holder for that circuit.

If you replace the stock fuse block with a bigger one, start off by rewiring the stock connections on two of those fuses then add your additional accessory wiring as needed.

IMPORTANT NOTE: Always use the British Standard for wire wire colours (Series IIIs are wired to an updated standard & some of the colours are different from the chart in my web site)

And ALWAYS document your additions and changes to the stock wiring harness in the form of a nice neat wiring diagram. Create a small binder or folder that stays in your vehicle that contains a copy of your truck's wiring diagram and keep a second copy at home with your manuals.

Relays:

The headlamps and horn draw a lot of current and the resistance of the circuit can cause them to perform a little less than optimum. Also the headlamp circuit is not up to handling higher wattage bulbs. You can correct this by adding relays. The ideal place is along the existing circuit pathway. For SI & SII it is on the bulkhead before the wiring splits sending power for each headlamp along opposite wings. For IIA & III the best place is along the right inner wing in the path of the harness. One relay for the high beams (blue/white) and one for the low beams (blue /red).

The wire coming from the foot switch goes to one side of the relay coil. The other side of the relay coil goes to ground (black wire). The wire coming from the headlamp goes to one of the contact connectors. The other contact connector goes to always hot 12V (big brown wire). make sure you have a good clean ground at your headlamp ground and you will get maximum brightness from your headlamps and can use higher wattage lamps.

Your horn is wired one side to always hot 12V and the other side to the horn button that makes a ground connection when you push the button. However the horn button doesn't always continue making the best high current ground connection over time. You can place a relay between the horn and horn button to correct that. The wire from the horn button goes to one side of the coil. The other side of the coil goes to always hot 12V. The wire from the horn goes to one of the relay contacts. The other relay contact goes to a good ground. Now you always get maximum volume out of your horn.

If you have some training and a lot of experience in reading schematics and electrical wiring you would not be asking this question in the first place.

If you read wiring schematics fluently, you can wire the schematic in your sleep and you have a truck with a lot of wiring changes and additions I suggest scratch building a harness using wires with insulation that follows the British Standard.

Just decide how you want to route the wiring harness and build it one circuit at a time. Run the wires for that circuit, test it then run the wires for the next circuit. as your harness grows, use tie wraps or tape to temporally hold the bundle in place to make sure that the wires will be the right length for wrapping. when you are done. When you are done you can wrap the harness. I usually wire the starter and ignition circuits first. They are just a few wires and that allows you to start and move the vehicle as needed while you build the rest of the harness.

On the last truck I rewired I tried something different. Instead of a nest of wires with barrel connectors behind the instrument panel I used a barrier strip attached to the bulkhead and ring connectors behind the main instrument panel instead of barrel connectors. This made for a lot neater wiring layout which makes doing work behind the instrument panel a lot easier. I have become a fan of this method.

If you have a vehicle that was wired positive earth from the factory and uses the NLA combination ignition and headlamp switch

The stock electrical system only draws a maximum of about 13 to 15 amps of power through the ignition switch. But if you add switched electrical accessories or higher wattage headlamps without relays you can over power the switch and break it. If you have a lot of switched electrical accessories the easy solution is to use a higher power continuous duty relay. On my truck the only thing that my ignition switch does is power the coil on a relay (very low power flow through the switch) and the relay provides switched power throughout the truck. Do that and you can accessorize to your hearts content and never worry about overloading a very expensive to replace NLA switch.

In closing: NEVER USE AN AMERICAN FUSE WITH THE SAME RATING AS A BRITISH FUSE

The British Standard for fuses rate fuses by the current that was guaranteed to make them blow instantly.

The American fuse standard rates fuses by the current that they will carry forever. The American 30 AMP fuse will carry a lot more current than a British 30 AMP fuse

I have a chart of equivalent fuse sizes. It is a good idea to follow the table if you don't want smoke to leak out of the wiring harness.

[o2batsea]

And remember that fuses protect WIRE, not the device at the end of the wire.