Halp Electrical people, help with a car project?

[Mr. Argumentor]

So, I have severe electrical issues with the Mustang. Bad enough that I am planning on running my own wiring for the head and tail lights, as well as a brake switch and that stuff.

I have H4 bulbs for the headlights, the tail light/brake will be 1157 bulbs.
I have found a couple decent websites that give plans to wire everything, but I'm horrible about actually doing the math and such to build a circuit that won't burn up on me. I'm good at troubleshooting an existing circuit or tracking down a problem with an existing wiring diagram, but building it makes my mind boggle
http://www.danielsternlighting.com/
http://www.allpar.com/fix/electrical/headlights/index.php


I wasn't going to use any of the parts in the car for this, I have a small bank of switches and I was planning on using the first to turn the headlights on, the second to switch from low-beams to high-beams.
Of course, brake lights need to come on no matter what, so I should be able to just use a fused circuit straight from the battery to the switch to the bulbs, correct?


I'm honestly now sure what I'm looking for here, just any advise and help I could get.
@gee @someone else

 

[CletusJones]

I'm good at troubleshooting an existing circuit or tracking down a problem with an existing wiring diagram, but building it makes my mind boggle

Early mustangs are ridiculously documented. Troubleshoot your existing setup? Ready to install harnesses are available and plentiful.

I wasn't going to use any of the parts in the car for this, I have a small bank of switches and I was planning on using the first to turn the headlights on, the second to switch from low-beams to high-beams.

Kind of a cool idea, I bet you could do it with the standard wiring, if you pulled the leads from the plug to the headlight switch. The low/high toggle is as simple as relocating the button from the floor to a switch in the panel. Then you can use the button for other fun stuff. Or send it to me. (PO box 470, 60452)

Of course, brake lights need to come on no matter what, so I should be able to just use a fused circuit straight from the battery to the switch to the bulbs, correct?

On my E30 and all other BMWs I've been in, nothing but parking/city lights and hazards work with the key off. You should do whatever ford did from the factory. Did the lights work before with the key off? They do on my uncle's '66.

 

[Mr. Argumentor]

Early mustangs are ridiculously documented. Troubleshoot your existing setup? Ready to install harnesses are available and plentiful.

Briefly went through this in my car thread. I'm a po, broke college student. The harness I am planning can be built for roughly $50, a full harness ends up being $700-1000, and I still might need the under-dash harness which is another $700.
The wiring in the car has been absolutely butchered, combine that with corrosion from rain and leaks as well as corrosion inherent in 50 year old wiring and the time investment to troubleshoot and fix is much more than it will be to build one. When I have time I play with it, but going through it completely is a losing proposition at this point.

Hell, I don't even need the electrical for most of the gauges.

Kind of a cool idea, I bet you could do it with the standard wiring, if you pulled the leads from the plug to the headlight switch. The low/high toggle is as simple as relocating the button from the floor to a switch in the panel. Then you can use the button for other fun stuff. Or send it to me. (PO box 470, 60452)

I don't really want to use the stock wiring for most of the reasons listed above. I want something I won't have to worry about.
It'll let me start fresh, I won't have to worry about all the other shit in there

On my E30 and all other BMWs I've been in, nothing but parking/city lights and hazards work with the key off. You should do whatever ford did from the factory. Did the lights work before with the key off? They do on my uncle's '66.

Oh yeah, just like modern cars, all the lights work with the key off. At least, all the modern cars I have played with.
Strangely enough, the starting/charging system works just fine.

 

[Mr. Argumentor]

Hell, I'm planning on pulling all of the fuses when I get my auxilliary system up and running, just leave the starting/charging fuse

 

[gee]

Honestly, don't butcher your car's wiring. Try to keep it as stock as possible, it'll remain far more serviceable - if you have to debug the car in the future, you'll be cursing yourself if you didn't keep stock wiring colors. And it'll make the car worth more - if you ever decide to sell your car, if they crack the hood and see homemade wiring going to the headlights, that's a red flag - regardless of how well it's been done.

If getting a painless harness is outside of your budget, keep an eye on junkyards, and even online. There might be someone in your area with a good used harness, or maybe good parts of harnesses you can splice into yours.

You'll need good connectors and good tools. Things like this are garbage, never use them on a car:

http://www.ebay.com/itm/176-Solderl...it-with-Crimping-Wire-Stripping-/160663474836

Using good connectors and a proper crimp tool (a good quick-connect tool can be >$100) is a must.

 

[Mr. Argumentor]

I'm not going to butcher my car's wiring, it's pre-butchered. I'm planning on adding a completely different wiring harness that is zip-tied in place next to my stock harness, I won't even touch my stock system.

I plan on getting a Painless setup at some point, but I'm going to do that after I complete the bodywork, at that point I'll remove this thing (or sooner)
Selling the car isn't an issue at all, ain't gonna happen

 

[gee]

I'll make a longer post shortly.

 

[Mr. Argumentor]

I'll make a longer post shortly.

I would appreciate it.
And I wanna be clear that I will do this (just need tail light sockets, and relays), but I would like to know how to do it safely.

 

[Mr. Argumentor]

So, I'm starting off with trying to figure out how to make the relay the weak spot so that it will trip before any wire gets hot enough to melt/burn and cause danger to the car (of course I'll have a a fuse before the relay as well)
For the headlights I'll be hooking 'em up with 12 gauge wire and they will have roughly 5-6 feet of wire between the bulb and the relay, I'll also be trying to keep the relay within a foot of the battery.

Based off of one of those websites above, a 15A relay will work to prevent damage to the wiring, but I'm having a hell of a time actually finding a 15A relay. How high can I go and keep it safe?

@Domon you get in here as well

 

[gee]

I wouldn't do the parallel wiring harness, I'd patch up what's there. The wiring harness in that car seems fairly simple, it won't take that long to diagnose it and won't be any more expensive to patch it than running your own parallel harness. Even if you do run a parallel harness, it might not fix anything that could be wrong with connectors, switches, etc.

Wiring itself generally never goes bad, unless it's something like a harness that goes into a door or goes through a firewall and gets chafed. Usually wiring problems are the result of bad connectors, or bad devices (switches, light sockets), or in the case of a lot of older cars, especially those that see road salt, bad grounds.

Here's what I suggest doing:

- Find a wiring diagram for the car, and borrow a good DMM with good leads.
- Pull the fusebox, and see what condition it's in. If the fuse holders are loose, corroded, broken, etc. try to source a new one. Make sure fuses latch well into it.
- Start pulling switches to probe them - headlight switch, turn signal switch, etc. Make sure the connectors come in/out of them smoothly - they shouldn't feel loose or "grind". Inspect where wire goes into connectors and make sure it's not corroded. Then using the wiring diagram and the DMM, run switches through their positions and make sure they measure open when they should, or a decent low resistance (equal to having the DMM leads touched together)
- Label the harness in a number of places so you know how it goes back into the car. Also label it anywhere it goes through a door, firewall, etc. Start disconnecting it from everything - inspect any chassis grounds on the harness and makes sure both the wire connector and the car body itself are both in good shape.
- Pull the harness out of the car, put it on a table. Give it a good inspection over its length for any broken/frayed wire, especially in spots where it went through doors or through the firewall. If there's bodges/crimps/etc added to the harness, inspect them - personally I'd remove those and replace them with good dual-wall heatshrink crimp lugs, done with a good crimp tool.

Once you've done all this, chances are you've found a number of things wrong. Fix 'em up, replace any bad switches, throw the harness back in the car, and you should be good to go.

 

[Mr. Argumentor]

And I wanna be clear that I will do this

Doing this the way I'm talking about will be a matter of hours, pulling the entire harness with it's old, brittle, corroded wires will take days if not weeks.

 

[CletusJones]

Dude, you've been told the right way to do this.

I don't understand the rush to get this done quick on the cheap, especially as you've said you plan to keep the car indefinitely. You've got plenty of time to take your time and do it right.

It takes twice as long to half-ass something because you've always got to redo it later. Do it once and be done.

 

[Mr. Argumentor]

Why do you think I'm half assing this? To me, half assing is repairing a harness that is old and broken. I don't care about keeping this car stock, I plan on replacing any wiring harness in the car with a completely new one when I get bodywork done.

I'm not in a rush, were I in a rush I would take out a loan and drop the car off somewhere and have someone install everything.

I'm not in a rush, I just don't want to waste time. I haven't driven this car in over 5 years and it kills me. I'm not in a rush, I'm not half assing things, I just don't want to waste my time on a system that is not worth my time.

I don't want advice on what to do with the harness, I want advice on how to wire this new system safely.






I feel like NME defending raw feeding

 

[Mr. Argumentor]

A secondary reason to get a headlight wiring system in there is that from the factory Ford used wiring that did not allow enough power for the lights to be at their maximum output.

 

[someone else]

I wouldn't do the parallel wiring harness, I'd patch up what's there. The wiring harness in that car seems fairly simple, it won't take that long to diagnose it and won't be any more expensive to patch it than running your own parallel harness. Even if you do run a parallel harness, it might not fix anything that could be wrong with connectors, switches, etc.

Wiring itself generally never goes bad, unless it's something like a harness that goes into a door or goes through a firewall and gets chafed. Usually wiring problems are the result of bad connectors, or bad devices (switches, light sockets), or in the case of a lot of older cars, especially those that see road salt, bad grounds.

Here's what I suggest doing:

- Find a wiring diagram for the car, and borrow a good DMM with good leads.
- Pull the fusebox, and see what condition it's in. If the fuse holders are loose, corroded, broken, etc. try to source a new one. Make sure fuses latch well into it.
- Start pulling switches to probe them - headlight switch, turn signal switch, etc. Make sure the connectors come in/out of them smoothly - they shouldn't feel loose or "grind". Inspect where wire goes into connectors and make sure it's not corroded. Then using the wiring diagram and the DMM, run switches through their positions and make sure they measure open when they should, or a decent low resistance (equal to having the DMM leads touched together)
- Label the harness in a number of places so you know how it goes back into the car. Also label it anywhere it goes through a door, firewall, etc. Start disconnecting it from everything - inspect any chassis grounds on the harness and makes sure both the wire connector and the car body itself are both in good shape.
- Pull the harness out of the car, put it on a table. Give it a good inspection over its length for any broken/frayed wire, especially in spots where it went through doors or through the firewall. If there's bodges/crimps/etc added to the harness, inspect them - personally I'd remove those and replace them with good dual-wall heatshrink crimp lugs, done with a good crimp tool.

Once you've done all this, chances are you've found a number of things wrong. Fix 'em up, replace any bad switches, throw the harness back in the car, and you should be good to go.

There is absolutely nothing here I will disagree with, and for the most part is exactly what I would have said. Honestly, Canare makes a real good crimper and dies for not a whole ton of money. I think most of the dies run $75-85 bucks, and the crimper itself is maybe $100? You probably can get away with just one die for the car.

A secondary reason to get a headlight wiring system in there is that from the factory Ford used wiring that did not allow enough power for the lights to be at their maximum output.

You do know you can just replace the section for the headlights with thicker gauge wiring, plus better grounds and solve this issue without running a separate harness.

But, since you don't want to listen to reason and just want to be cheap and impatient, heres a few tips:

Since you're saying you can do this for "less than $50", you're probably not using the best wire, and I'm positive it is all the same color. Save yourself the headache and label everything fucking religiously. In the same vein, be prepared to do this 3 or 4 times since you can't get a decent pair of crimpers, never mind the die set and connectors for $50. You're going to be tracking down issues the entire goddamn time you have this in here because of this. At this point, I'd rather solder because at least that will give you a decent connection until the solder connection breaks from heavy vibration.

Honestly, I'd just replace bit by bit at a time, you can do it piecemeal and not spend a ton of money, even with the same colored wire - just label everything religiously. If you dont do it properly, it will literally give you problems the entire time.

 

[Mr. Argumentor]

You do know you can just replace the section for the headlights with thicker gauge wiring, plus better grounds and solve this issue without running a separate harness.

But, since you don't want to listen to reason and just want to be cheap and impatient, heres a few tips:

Since you're saying you can do this for "less than $50", you're probably not using the best wire, and I'm positive it is all the same color. Save yourself the headache and label everything fucking religiously. In the same vein, be prepared to do this 3 or 4 times since you can't get a decent pair of crimpers, never mind the die set and connectors for $50. You're going to be tracking down issues the entire goddamn time you have this in here because of this. At this point, I'd rather solder because at least that will give you a decent connection until the solder connection breaks from heavy vibration.

Honestly, I'd just replace bit by bit at a time, you can do it piecemeal and not spend a ton of money, even with the same colored wire - just label everything religiously. If you dont do it properly, it will literally give you problems the entire time.

That is literally what I am doing. I am replacing the headlight section of the wiring harness. I am not worried about gauges, I am not worried about interior light, I am not worried about turn signals.
Headlights with high and low beams, and brake/tail lights.

I am friends with every manager (except the asshole getting fired) at an auto parts store that I used to work at. I still get employee pricing.
Black wire for ground
Red for tail light and low beam (as they are on the same switch)
Yellow for high beam and brake light.
I was already planning on soldering. I may have a friend with decent crimpers that will let me borrow them.
I understand that longevity might suffer by not properly crimping, but within a few short years I hope to have her apart and doing paint and bodywork on her. I am planning on changing everything out relatively soon, however not soon enough that I can just put it off

At this point I have to get her on the road to find out what the serious issues are because old cars rot if they are not used. The condition she is in now Vs when I dropped her off at my dad's place is staggering.


I understand not wanting to participate in a hack job, I have had to go behind dozens of mechanics that had no clue how shit worked and it is horrible. I already have those problems with this car due to previous owners and friends that thought they were helping me. However, I am not asking anyone else but me to work on the car, if I fuck up on this setup it will be my fuckup. I will own that fuckup. I am not going to ask you or anyone else to help me fix it because at that point I will be able to take care of it on my own.

My sole concern at this point is making sure I am not going to burn my car down, and to that end I am trying to get the fuse and relay capacities correct. If you can help me with that I would truly appreciate it.



To anyone who thinks that I am being snotty or arrogant, I apologize as that is not my intention, but please understand that this car is my passion and one of my greatest sources of enjoyment. Please go re-read through my thread about the time I have spent working on her and realize that I am not looking to cobble something together.
As much as someone can love an inanimate object, I love this car. By that token I will do what I want to with her, but I want to be as safe as I can with what I am doing.

 

[CletusJones]

At this point I have to get her on the road to find out what the serious issues are because old cars rot if they are not used. The condition she is in now Vs when I dropped her off at my dad's place is staggering.

Since you're planning to strip the car and do bodywork, why not just get started on that? If you're going to restore it, it doesn't matter what the existing condition is since you'll be rebuilding everything anyway. All serious issues will become apparent as deconstruction/documentation progresses.

The only thing I've gotten from this thread is that you just wanna drive your car right fucking now. Take a step back and rethink this. Any money you spend on a bullshit bandaid fix now is money wasted. Take your time and do it the right way the first time, you'll save headaches and monies.

Three people are telling you the same thing, maybe give us a chance?

I determined my E30 needs suspension bushings, so I began purchasing parts to overhaul the entire underside of the car. By having a plan I was able to save myself over $600 vs just buying everything at once, more if I would've considered buying used parts.

My point is this: do you have a project plan for the car? If not, spend $20 on a thick notebook and some pens and put something together. You'll save yourself a ton of headache down the line. Planning to rebuild a car is no different than planning a corporate project. You explore multiple possibilities and document the process. Make a final decision and keep the plans to refer back to.

 

[gee]

I can't propose any means of adding new headlight wiring etc. and be able to guarantee that it's safe, because at some point you'll be using switches/connectors/etc that are part of the original car. And that's the stuff that tends to go bad, not necessarily the wiring harness itself. You'll have to tear that stuff apart and make sure it all works. Again, it's less trouble to evaluate what's there already than it is to run new wire.

I'm in full agreement on the project plan idea. Come up with a plan, cost estimates, etc. and start going through it systematically rather than rushing to get the thing on the road. Not driving the car now won't hurt it, the car won't rot from disuse provided it's stored in a reasonable environment - park it in your garage and keep a dehumidifer running out there, you'll be fine.

There is absolutely nothing here I will disagree with, and for the most part is exactly what I would have said. Honestly, Canare makes a real good crimper and dies for not a whole ton of money. I think most of the dies run $75-85 bucks, and the crimper itself is maybe $100? You probably can get away with just one die for the car.

You don't need to spend bucks on a Canare crimper. Get one of these, it's just as good and costs a whole lot less - http://www.digikey.com/product-detail/en/0640160037/WM9986-ND/821379 - and you can probably get it from somewhere else for cheaper.

 

[Mr. Argumentor]

Since you're planning to strip the car and do bodywork, why not just get started on that? If you're going to restore it, it doesn't matter what the existing condition is since you'll be rebuilding everything anyway. All serious issues will become apparent as deconstruction/documentation progresses.

The only thing I've gotten from this thread is that you just wanna drive your car right fucking now. Take a step back and rethink this. Any money you spend on a bullshit bandaid fix now is money wasted. Take your time and do it the right way the first time, you'll save headaches and monies.

Three people are telling you the same thing, maybe give us a chance?

I determined my E30 needs suspension bushings, so I began purchasing parts to overhaul the entire underside of the car. By having a plan I was able to save myself over $600 vs just buying everything at once, more if I would've considered buying used parts.

My point is this: do you have a project plan for the car? If not, spend $20 on a thick notebook and some pens and put something together. You'll save yourself a ton of headache down the line. Planning to rebuild a car is no different than planning a corporate project. You explore multiple possibilities and document the process. Make a final decision and keep the plans to refer back to.

There are dozens upon dozens of factors that relate to how I handle working on this car. Very very few of them are directly related to the car and are generally not talked about on here, but lets look at a couplefor shits and giggles.
My garage is too small. My lease is up this summer, so we might move, we might buy a house. To do the bodywork I will need room for a decent welder, bottles of gas, either a plasma cutter, a decent sized air compressor, or (more likely) both. All of those things are expensive as fuck. I will need room to move around the car and crawl through it. Say we do move, without working lights I will have to spend money to put the car on a trailer again. At some point in the relatively near future I am going to have to work on wedding plans.

My life is just too damned unstable for me to start on big projects, so I am not going to. At the same time working on and driving this car are my two biggest methods of relaxation, so for me to not work in my garage is damned silly in my mind.



From my point of view three people who mean well but have one small fraction of the story are trying to convince the guy doing all of the work and who sees the entirety of the story what to do. I would bet that everyone telling me I am wrong has a manager or supervisor at their job that does not understand several key factors of their job that nevertheless tells them how to do their job.

Let's look at it another way. How would you feel if I told you that the stitching and the colors you used on a project for a customer were completely wrong and you needed to redo it from square one?
Would you tell me to fuck off? Would you ignore me? What if I kept questioning you on why you were doing it that way?

 

[Mr. Argumentor]

I can't propose any means of adding new headlight wiring etc. and be able to guarantee that it's safe, because at some point you'll be using switches/connectors/etc that are part of the original car. And that's the stuff that tends to go bad, not necessarily the wiring harness itself. You'll have to tear that stuff apart and make sure it all works. Again, it's less trouble to evaluate what's there already than it is to run new wire.

I have new switches and completely different plugs and connections.
I am not using anything with the stock harness, not the wiring, not the switches, not the fuse block, not the plugs for the lights. Nothing from the stock harness will be used.