Technical Rebel Wire Harness diagrams and wiring info

I have a question I did not see addressed.
Is a fusable link merely a wire 2 sizes smaller than the rest of the circuit or is it a wire made of something special?

 

Rebel43...

First of all let me thank you for this thread, lot's of very useful information. I used your 9+3 kit on a '46 Ford, several years ago, that I had bought with little to no wiring, it ran and the headlights worked on low beam, that was about it. I found your kit simple to install, I did have a problem with the turn signals but that was quickly addressed with one simple phone call. Thank you for that.

I am currently preparing to tackle the wiring mess in my '51 Oldsmobile 88, I have been having starting problems and a engine miss that I have tracked down to being low voltage to the Pertronix ignition. I am only getting 5.08 volts to it and it requires a minimum of 5.2. I had debated on installing one of your 6 volt harness's but have finally arrived at the notion of just wiring it myself. The lighting system seems to be in pretty good condition, someone had rewired it in the past so I'll leave that alone. The charging system is mostly frayed wiring and the starting system is made up of a lot of frayed wires and poor splice jobs that were done with, I think, too light of gauge wires. I plan on referencing the wiring schematic's that are in my 1957 edition of Motor's Auto Repair Manual as it shows the color code and what gauge wire goes where. My question is this, is the cloth covered wiring the same gauge wire as the newer insulated wiring? In other words, when it call's for a 10 gauge cloth covered wire is it the same size as the modern stuff? If the wiring is the same size, is there any need to go to heavier wire? Thanks...

 

You can buy small rolls of fuse link wire in various gauges. It's made to burn out like a fuse if the current gets too high and the insulation is different from normal wire to help prevent a fire when the fuse link burns out.

 

Why use fusible link rather than a mega fuse?

Phil

 

A mega fuse is the way to go and protects most of the wiring. I have a 50 amp one in my car between the firewall mounted solenoid and harness wiring from the fuse panel.

 

I even run a mega fuse on my little bucket...

 

The wire (cloth covered or other types of insulation) should be the same size, gauge wise, just using a different insulation, so a cloth covered 14ga should be the same conductor size as say an SXL 14ga. Just use what is called for in the 6v system and you would be good. You wouldn't need to go heavier if you're just changing to cloth insulation.

 

We've had guys swap out to a maxi fuse instead of the fusible link. It's just preference I think. In about 14 years or so we've had 2 fusible links blow, one was a wrench dropped and wedged between a starter hot post and exhaust and the other was an ignition switch that wasn't yet permanently mounted and pushed through the dash and arced out heavily. I've still got 60's cars with the original wiring and fusible links installed. If I was going to swap to something else, personally (and I'm just the tech guy with my own opinions) I think I'd do an auto resetting circuit breaker, but once you get over 50amp they get bulky and expensive, again just me thinking out loud. All of these options serve the same purpose. They're all meant to blow before blowing out the bus bars inside the fuse panel.

 

Just wanted to post this, as wiring tech in general. I know you've all heard different ways of wiring an alternator...don't use an indicator bulb, use an indicator bulb, use a diode, use resistor wire or a resistor...well, In my spare time, which is little, I've been rewiring a 62 Buick Electra for a friend, and I just tried out the alternator and regulator. He bought the car at an estate sale and the wiring was trashed, probably some of the worst I've seen, almost. He couldn't run the car enough to know what worked and what didn't, so after I wired most of the car, I fired it up to check the charging system. Here's a link to the video, If it doesn't work, I'll get it off my phone and post it. This is with the exciter wire just run to the old voltage regulator, the dash isn't in yet, I'm having to make some repairs to it. So there's no bulb inline in the exciter wire, no added diodes or resistors. There will be an indicator bulb later, but just because the dash has a provision for it.

Here's also a diagram for the wiring:

Link to the video showing battery voltage and charging voltage:

https://l.facebook.com/l.php?u=https://www.instagram.com/p/BtL7CB7HDG-/?utm_source=ig_web_button_share_sheet&fbclid=IwAR0CK0q8ZhoedI8xkjsui5D34k8AVrOPAzEuc8RVvkG_qKPzLWeMypZsC2Q&h=AT3nDNB0M0cadk2BfmH-dQnfmfTHwV80xRnvTZwKdu5kcRhstfp8qRjLjrC476tIkj3V7Qkhz5-Nd-TfsD-yAyTT63Jfly39LvCnB56olQ_Pds6ldwLyQuQ8-AC4ESd1dXmlC9y0qFiizazS7MT-nvKDJypz4w8rad4fg375o4Tyxxfa75UdOYbDsmnpzWK7KmBkcjGrzpEsTrANWSBcwkaQy-vYPe9rwqChrO2oAxWMIbuaL4tzzaHT57g3_wQ9Mxi2y1BFOf6YEZU1iQyZa__4Yx-oTe6uPPBclF5BFDriL-x6MPNTggVEy_WJ8MNA6B6Z1Gnyk3FS2d2RSD58xR90r9vKWa5JIyI6JyPtRc1rMW_GXHqJrMRFrzde9eb_ugVEcvqFGkFaIWvlqu_w8ybnjBKAOgh_ql7n7pyjHE_qdnUkd_8mat0KfLMjZU6yQ-tSnLYQbMu6DGd0ASDVpYgExAfR7Kiiwq34BSdyKlfY6FA62mZStafrfnbenlSiKdq3aBvGpunKahWlYFlW9GKhpLGMHRFzTVKvF9Fe0c0jnXd19q2AxDgoWb6hCCzLkS7cUJnmaOyV_8gqv4xhBaQrdu6xUutpcAueMxxf3o7FgSaZfY3SbFYXxV6JBxRrBxJw-21i77T8kiH5yEGHbIAY0-xJ

 

Video works, thanks for the info. External regulators are something that I avoid.

 

We weren't sure if his old stuff was any good, but it looked good and had potential. So I just made up a new charging harness and routed it from the alternator, across the core support, and over to the regulator, reusing the old connectors. It worked out though, better than changing brackets and whatnot on the nailhead engine, and I like to use what I've got if it's not too much of a pain

 

This diagram is from an old Peterson Hot Rod book of the late sixties. It's how I wired my '55 Chevy truck. The alternator is an old Delcotron 60 amp

 

Right, same setup as the Buick I'm working on, I just haven't fixed the dash yet so the indicator bulb isn't inline between the switch and the regulator. His circuit board was trashed so I'm taking it off and just putting individual 2 wire bulbs in place of all of them and wiring them into a connector

 

........Hi hope you can help me,...I have a (new) wiring harness which has 2 2 prong flashers...., the purple wire is for the turn signal and the brown is for the 4 way.... I also have a after market 4 way /turn signal that has 7 wires. The wiring diagram that came with the turn signal shows a 3 prong flasher and shows the blue wire connecting to the P terminal, the black wire connecting to the L terminal.. My question is can I do away with the 3 prong flasher and use the 2 2 prong flashers and still have turn signals and 4 way? I f so where do the wires blue, black, purple and brown connect?.. See attached picture. Thanks Miller

 

Sounds like you have an American Autowire kit, they use the colors you have ( purple and brown) as you described.

Here’s a video they made on the subject but when I watched it I still wasn’t clear on how to make it work.

I ended up going with a Rebel harness and that will make it a lot easier.

There may be a easy way to do what you want to, maybe Jeremy can help you out.

 

...Thanks for the info.. after looking at the video I agree with you,it is not clear..thanks miller

 

Do you need the indicator light in the turn signal switch?
If not you have 2 choices-
1. eliminate 3 prong flasher, connect brown harness wire to black switch wire. You'll have turns and 4 ways that are "hot" all the time, ideal for 4 ways, just don't forget your turn signal is on sometime.
2. eliminate 3 prong flasher, connect purple harness wire to black switch wire. You'll have turns and 4 ways only with key on, not ideal if you actually need to use 4 ways.
In either case above if you have 2 indicators in the dash they can be tied into the front turn wires.

 

.....Thanks for the info. I think you gave me the answer and the way to go. Thanks again miller

 

....and if you want to use the pilot light in the switch; connect the blue switch wire thru diodes to the left and right front signal wires.

 

Great advice all around! Just saw this when I came in this morning but you guys beat me to it. The 3 pin flasher is basically a 2 pin with an added P (pilot) terminal and all it does is work the indicator light in the body of the switch, so if you're running dash indicators (or no indicators at all), eliminate it and wire as 24riverview suggested. As RichB suggested you could also wire the pilot to the 2 front turns using diodes, so it can't backfeed to the other side. It would get a hot from the side flashing and it's self grounded in the housing.

On the diodes, you can see the gray bands on the end of the black center of the diode. That means that power can flow though, band toward what you're powering, but not come back out. Otherwise you'd be giving it a path into the other front turn wire. Great tech support here guys, let's keep sharing this info and put these mysteries to rest!

 

....Thanks to all for the quick replies and ...Miller

 

I had this same issue with a customer's vehicle awhile ago. I didn't want him to have to have the key on to run the 4 ways so I split the power supply with a switch. For normal everyday use the switch would power up the signal flasher with key on power. If there was a need to use the 4 ways, a simple flip of the switch to the other position would send battery power to the 4 way flasher and he could take the key out of the ignition and lock up the vehicle. It might seem a little fussy, but since rewiring the vehicle he hasn't had to call a tow truck. I don't expect he will wear that switch out anytime soon.

 

Excellent idea! Put a SPDT toggle out of sight, connect black wire to center terminal, brown and purple to outside terminals.

 

....Can you post a wiring diagram showing what color wires connect to the switch etc ?...thanks Miller

 

I hate that these switches are still built to work off of one flasher (everything keyed or everything constant). I had tried to use a 5 pin flasher, like an EP27 I think, to give it 2 inputs, one keyed and one constant, but i quickly hit a brick wall once I remembered that the switch still works off of 1 load wire, so whatever your turn signals are powered off of, so are the hazards. I wish someone would remake this switch using 2 different load wires for turns and hazards. I like the toggle switch idea by the way!

I've used simple little SPST switches running to a flasher, and 3 diodes to make a simple hazard switch (for 1157 rear bulb setups). Similar to a Ford setup, but with a simple switch. A simple pull switch and diodes would also work, spliced into the left front, right front and brake wire. Stuff like that is when it gets fun!

 

Generally because you can get more accurate overcurrent protection with a fusible link under certain conditions.

The first thing to remember is overcurrent protection is there to protect the wire, and only the wire. If a component fails, overcurrent protection isn't going to 'protect' it. It may prevent catastrophic damage to the component at best. The second thing to know is you're actually protecting against two kinds of overcurrent; short circuits, where some part of the circuit goes fully to ground, and overloads. A overload is where current increases to above the circuit rating but may not be a dead short. A partial short to ground or a failing component can cause this.

On a single-use circuit, a fuse is the best choice. You have a known load that won't vary (or won't vary much), size your fuse to 125% of the load to avoid nuisance tripping (and size the wire to the fuse size) and you're good to go. Fuses will blow when they reach their rating (within +/- 5%), you don't have a 'cushion'.

But if you've got a circuit where the load does vary, a fuse will start having issues. A few examples...

The charge wire from the alternator or generator is one. The OEMs don't fuse these as a rule due to the difficulty of sizing meaningful protection. Let's say you've installed a 140 amp alternator. It seems the typical wire size used is a #8 which is rated at 40amps. Now that's fine in most cases, few cars draw that much just going down the road. For proper overcurrent protection, you'd want a 50 amp fuse (40 x 125% = 50). But what happens when you have a low battery or a hard-start where alternator output jumps up to 100 amps or more before tapering off? Bang, the fuse blows. Install a fuse large enough to withstand that, you have now lost your overload protection. Now a partial short (as long as it doesn't exceed the fuse rating) will be free to sizzle away, at the least damaging the wire and possibly starting a fire. You can have the same issue in the power wire or wires going to your fuse panels. Here you have continuous loads and intermittent loads (things like the horn, turn signal, cigarette lighter, etc) that can cause your load to vary by 50%. Same issue as the alternator example above.

Enter fusible links. A fusible link is designed to withstand temporary overloads. The fly in the ointment is how long it will withstand it varies with the amount of current. I've looked in vain for 'current slopes' on these to determine the time/current relationship to no avail. They are designed to 'clear' a dead short quickly enough to prevent wire damage, but if sized too large will not prevent overload, so you're back to square one. In fact, a fusible link in the alternator scenario above could possibly allow more damage compared to a fuse.

Generally speaking, if the maximum current is 130% or less of the wire rating, you'll have meaningful short circuit and overload protection with a fusible link. The higher the percentage, the poorer the protection.

 

...Thank you miller

 

Crazy Steve, I discussed both alternator and fuse block protection with American Autowire at their booth. He did not speak as an engineer like you. Just as a rodder wanting a PRACticle solution. Seemed the final answer was to not put protection on either circuit.
Seems your answer is similar in that there is no PERFECT solution. Thanks.

Phil

 

I'm not an engineer, just a retired electrician. One thing you had to know to be competent in the trade was overcurrent protection, plus I have pretty good knowledge of theory (just not engineer level... or at least a good engineer... LOL).

I'll agree with the tech; trying to 'protect' those wires with the limited information we have is extremely difficult. And guys forget, the OEMs didn't install fuses in those wires back in the day, and it was rare to see a major failure in them. Charging and ignition systems nearly always failed 'open', it wasn't until electronics and additional power accessories became prevalent that it changed. Fuse panel feeds had protection on all the circuits connected to them, so the only real danger on these circuits was if the wire became damaged and shorted to ground; careful routing/sizing of the wire would eliminate that.

Fusible links became popular with the OEMs in the late '60s. Not so much that it offered additional protection, but as a way to squeeze more capacity out of their harnesses without increasing the costs of the building them, as well as preventing major warrantee issues. Fusible links are much cheaper to replace compared to a burned-up car... LOL