Technical Biggest PRE WIRING Regret

I like to bring most wires to a terminal strip before going to a device. For example everything in the rear of my car ( lights fuel sending unit etc) is fed from a terminal strip mounted in the trunk. A terminal strip makes trouble shooting easier and is a good place to terminate spare or unused wires.

 

I just wired up my first hot rod with an American Autowire system it included every piece you need to do the entire truck ... Even practice terminals to perfect your crimping ability...Not the cheapest kit out there but pre terminated in fuse block an plenty of extra length on all wires an a very good wiring diagram of each circuit...And everything worked when I hooked up the battery...

 

I run a flat , 6 conductor wire which they use for trailers, under the carpet from firewall to inside the trunk. It is only about 3mmthick, X 25mm wide, and when you thinkabout putting in rearr speakers, a light the trunk or some other gizmo which needs a wire, it's all there, just conect up without having to rip everything out. I have installed fuseboxes and junction boxes directly behind the glove compartment on the firewall. You can still get to the fuses from below, but if you need to get into the works, the glove compartment liner can be removed , leaving everything visible .
A wiring diagram with all the bulb sizes, original switch types (What headlight switch did I use???), wiring colours, etc is a must. (Make a copy and stash one away, if you ever sell your ride the next buyer will know what youve done and what parts you have used.

 

Locate the fuse panel under the seat or hinge it on the bottom of the dash so it swings down for easy access. Use a wing nut to keep the panel tucked up out of sight.

Keep the wires neat by threading them through wire ties at the corners and along the straight runs, then replace the wire ties with Adel clips to finish up.

If wires are exposed, cover them with the black cloth type wire covers available from several suppliers. They tidy things up and look a lot better than bright colored wires or corrugated plastic covers.

If wires aren't marked, add a masking tape "flag" at each end and label the flag with a fine magic marker. If the wiring is out of sight, leave the flags on because they come in handy when you need them later. And you will.

Go slow and remember, each wire only has 2 ends - just make sure each is connected where it belongs.

 

Some fantastic tips here, wish I had seen this thread a couple of years back!

 

I worked in a truck paint shops where we had to remove the lights at the frame to blast and paint it. And them re install.
Even pros don't give a beep about who is gonna re do it.
I usually plans to run them in a way that makes it possible to re move one cable and re do.
Instead of finding the one wire, I do them as a set. I run Left Front Lights in one Trailer cable, 7 wires and insulated in rubber. I use a good make, with think insolation and big wires.
That means if I get an issue with left front. Just yank full cable, install new ones. I use what we reveres to a 7x1.5 square mm cable for most of my lights, and run truck/Trailer stuff because of the heavy insulation. And speaker cable that is 2x2.5 for heavy stuff, not lights.

If it's a frame based car, it run a ground in every cable, and ground it by the "receiver", and connect it with the lamp ground, and ground them together. Just to be sure!

I remember to carry extra fuses, because the old pill style is not something they have everywhere anymore. But you could go for a modern fuse.

And use good labels in the cab to separated cables, because if you use my method they all be black by the fuse box.
On my Volvo I run two fuse boxes, small and old. One for stock wiring set up and one for aux, then I'm always sure to make it home on one fuse, the engine is stand-alone.

 

So many good tip's and advice going on here,so if you pick a lil from everything,you shouldn't have any issue's,but there always are......Some only general advice I can offer is- Run one circuit at a time,(like it's your only task),always measure 7 time's before your final cut/crimp,Plan for grounds accordingly, And possibly add a "service loop"= meaning,if you ever have to service anything,don't make it to where it's a PIA to take apart again.
One other thing I have found, (from experience)and from a previous posted picture of the clamps above,is that on those,the rubber will deteriorate(crack),and look like s%it. I use the coated clamps on things,and they last forever...... Jump in and go for it! But,just don't let the smoke out!

 

Fully wire the car and get it running and through a shakedown period before painting. Leave extra slack the first time, as you will need to cut wires/plugs/connectors for removal during disassembly prior to paint. That way you will get all the holes, hold downs, and grommets figured out. ...and if you need to fabricate a cover to hide some wires, it can easily be done without damage to paint. I also add many extra ground wires to components that might lose a good ground due to paint. Think through wiring routes and don't be afraid of adding relays for headlights, horn, fuel pump, etc. in order to reduce amperage in wires under dash and to shorten wire routes for heavy draw components.
... and don't ever do wiring in a single color, especially black!

 

If you're building floors in the car anyway, bend up a "hat" section sheet metal tunnel to attach to the bottom of the floor rather that running the wires along the frame rails.

 

Funny, Mine is leaving extra circuits that will never be used. Opposite of everyone else.

 

I guess the biggest regret was not including terminal strips at the beginning and end of the extra wires. Any descriptive flags made from tape attached to unused wires would always fall off. Screwing the extra unused wires to terminal strips makes sense and is much neater than hanging wires.

 

How do you use the star washers when doing the wiring? The Adel clamps are pretty self explanatory.

 

Use many terminal blocks. That way if there is a problem you don't have to replace the whole wire just from the point of the problem to the terminal block. Also as many have said run extra wires in the loom.

 

I use star washers on every ground that is on the car........it bites into the metal surface and ensures a good steady contact despite vibrations.....Bolt through frame or sheet metal screws it works great for both. Rough up the metal, insert your fastener of choice, and you are grounded mister!

 

Be very careful when accepting help from a buddy that says "I'll help".................

 

Volvo build in a shallow u, in the floor pan. Made up a lid with two weatherstrips. So it keeps the water out. No water and no smoke is the way to keep you car running.

Simple and good advice

This is the cable I talked about

Takes a lot of abuse, run it straight from the headlight bucket to the fire wall.
Stands up to oil fumes and moderate amount of oil/undercoating, and nicks and bruses with out hurting the actual wires.

1 dot for left front, 2 dots for right front and so fourth.
Everything else I run in "loose" wires, and keep a foot extra wire.

And use a lot of these in dry spots, and make it easy to swap out the broken cable when having issues. Just use a good cable route.

Simple, and cheap, we used this system on a fleet of tow trucks, and it work like a charm.
And make a big readable shop diagram and hang it in your shop, and keep a copy in your car!!

 

Any additional information? Bob

 

Use new wiring, don't reuse old wires.

 

Only thing I can add is use quality wire, not cheap princess’s auto or harbour freight hard brittle junk with crappy insulation!

Use quality crimp tools and connections .

Ground is your friend.

Try keeping your fuse box and other stuff that may require serving accessible , while it’s nice to have everything hidden and smoothed our, having to do yoga to get to your fuse box or relay etc, sucks!

 

Bob, I think Horrible Freight has remote controllers. Maybe you can hook them up instead of wires. Just make sure you don't get the frequencies mixed up or the radio will come on on instead of the turn signal.

 

I ran all the circuits I didn't think I needed, like Elect Fuel pump, pre wired for trailer hitch etc, in case I need them later. I had to add an Elect fuel pump once and I was glad the wiring was already in the harness to the tail.
Use relays when necessary: Elect Fan, Horn, Fog lights, High Beam, etc.

I really like the paint under the dash white idea too.

 

Terminal blocks are your friend. They look older, are cheap, easy to work with and very helpful. Had to remove a rear fender after wiring. Took a couple screws loose and the light was disconnected. Draw a diagram and be prepared to change it a couple of times. Leave Wires Long...easier to shorten than lengthen!

 

This with the addition of the drivetrain being installed. What a PIA! Had to buy a right angle drill head to drill the holes for the harness retaining clips. Woulda coulda shoulda......

 

Wiring is my favorite part. Years ago, I was a mechanic at a Mercedes Benz dealer. The instructor at one of the schools was going over schematics. He kept referring to some larger electronic control components as FM boxes. Finally. someone asked what does FM mean. "Fucking magic" was the reply.

 

Another tip I have used. I mount two independant 4 or 5 fuse panels in the trunk. Especially when the battery is back there. One panel is battery powered, the other is ignition powered. It makes it easier to provide power to extras at that end of the car.

 

Even if you use a harness kit, take notes of anything that was special to the installation. I do a to-from list with colors and where they go. Then I copy it over so I can read it. I staple it into the harness instructions. Take pictures too. Things on my car that were hairy were the directional wires, hard to read the color codes, had to buzz the whole thing out.

 

Draw out your system first, have it on paper before you start.

 

I've wired a lot of cars over the years and helped wire a lot more.

Years ago I made my own fuse panels,used glass fuses & bought rolls of wire and I have used a lot of aftermarket kits,some of the kits were a joke and a PITA to use.

I have used & helped install 9 American Auto Wire kits and the beauty of this kit is everything you will need is included and enough wire to do 2 cars,this is not the case with some of the kits on the market.

The instructions are broken down to different color diagrams and is super easy,even if you haven't wired a car in the past.

I think my granddaughter could wire a car using this kit. HRP

 

Never try to carry any unused circuits in your bundle. It’s a lot cleaner eliminating them before you get started. Learned the hard way. There’s nothing worse than trying to find a circuit problem in a large bundle of unused wires.

 

Grounds are your friends, well not in your coffee but under the dash at least. I added two of these to my car, one other the dash and the other in the trunk. The are marine ground busses and I cabled them to the frame.

If your battery is trunk mounted, I recommend one of these. It prevents running an energized cable to the starter and eliminated "hot starts". Make sure it is grounded.

And run all of the accessory and charging power through a 100 amp breaker near the battery and then through one of these accessible from outside the car. It will kill a running motor and handy for long term storage.