From MP3Car.com Wiki
Ron Francis Wiring has graciously provided these electrical Tech Tips for republication on the mp3car.com wiki. Much of the information is geared toward the builder that is wiring a car from the ground up, but many of the tips are good information for our vehicle computing hobby, as well as anyone making any modifications to a vehicle that involve electrical connections.
At the request of Ron Francis Wiring, the Tech Tips have been reproduced here in their entirety.
Titles to many of the tips have been added to allow mp3car.com members to easily find tips based on general subject matter. Other than some of the titles, the information is 100% verbatim from Ron Francis Wiring.
[edit] Introduction
At RON FRANCIS WIRING, we believe that our customers deserve to be armed with as much knowledge as possible. The more you know, the more fun it will be wiring your vehicle and it will be a safer installation. You will understand WHY you may need certain packages, relays or problem solvers. No one wants to purchase something just because the salesman said so! At RON FRANCIS WIRING we don’t ever want to sell you something you don’t need. Let’s face it, a returned product costs everyone in the long run. We want to keep you in your comfort zone, and make your wiring experience as positive as possible.
This Technical Manual is full of information that was used in various articles, as well as our own newsletters and website. Some of it appeared in the August 2005 Super Rod by Buckaroo Communications, in the article titled, “Negative Grounds, Positive Results”, other information was in the November 2005 Super Rod article titled “105 Electrical Tips.” We tried to assemble the information in ‘quick snippets’ so that it is easy to digest and remember. Never be afraid to call us toll free and ask us to clarify any of the information you find in these pages!
[edit] Tech Tip #1 - Firewall Connectors
Copyright Ron Francis Wiring 2001
Firewall connectors came into being about 1955 or so when the big three realized they were in need of a better way to add accessories to their vehicles yet not slow production time hand wiring the cars and trucks. The plastic connectors used first in the 1955 GM cars introduced a whole new way to assemble the car on the line without delays or mistakes. Since Hot Rods and Customs are not mass produced, my first thought is why use something that has little purpose if you are custom wiring the car.
Firewall connectors started off as simple 8-10 wire plugs located on each side of the firewall and allowed the engine to be pre-wired before it hit the line. Mistakes in this light we dramatically reduced. In the 1960s when accessories started drawing more juice, the firewall plug started to show more of its shortcomings. Whenever you “un”wire a car for restoration, look at the wires and determine where the damage is. There will be some in the middle of a length of wire where some previous owner might have spliced something in. There will be some damage in the engine compartment where repair activity might have smashed a wire or damaged the insulation. Where is the worst? The burns, the melting? At the factory connectors and fire wall plugs.
These firewall connectors have terminals made of brass and are pressed together with friction and held there by a plastic housing which is busy trying to hold up to 20 or 30 other wires in place. The result is three sources or trouble. One being the wire to the terminal, second the two terminals and third the other terminal to the last wire. The result is a clear source of trouble and proven by the melted housing. WIRE WORKS has learned from these indicators and manufacturers their harnesses with out the need for a connector. In a vehicle being wired one off the straight copper wire can produce up to 80 percent more current without the risk of failure.
Brass can only carry 12-16% of the amperage the a similar sized copper terminal can carry. Copper of course is too soft for use in smaller applications. Between the loss of capacity and the other crimps and connections, certainly a straight piece of copper wire (times the number of circuits in the plug) can work for you much better.
We have to use connectors in some locations between switches and wires or other sensors and wires but why use them where we don’t have to? I started my career wiring cars with the 1960s Mopar vehicles that had firewall plugs that failed in use. I spent a lot of time splicing around the firewall connections to reconnect circuits. Reproduction harness have the wonderful points but I suggest to you that unless you are trying to “reproduce a factory vehicle, the connectors in the firewall need to be considered. IF you want to make a more reliable system eliminate that plug.
Look at what made the original fail, look at age and technology of the fire wall plug AND the fuse box. Did the fuse box have some melted areas? Why put back the same technology that failed under less load than you intend to put it thru. Are you planning A/C? Power windows? Do you think the original fuses held up OK without these heavy options? Plan ahead and consider modern technology.
[edit] Tech Tip #2 - The Fuse Panel - Where it should go, and WHY
Copyright Ron Francis Wiring 2001
Over the past 30 years I have been asked many times what I thought of installing the fuse box in the rear of the car, which I will refer to as the trunk. There seem to be many reasons to do so, some of which make good sense - until you consider the consequences.
There are many things that get in the way and use up dashboard free space:
Air Conditioners...
Air and Heat ducts..
Elaborate pedal assemblies...
Recessed fire walls reducing the space...
Cruise controls hidden behind the fire wall...
Ignition boxes hidden behind the firewall...
and many more that really do seem like a good excuse to make a decision that the wiring panel must go somewhere else. Some day soon a supplier will probably justify using glass inline fuses to reduce the space required to protect circuits. There already are some really small so-called harnesses, known at Ron Francis Wiring as "spaghetti", that seem to solve this very job. I guess this might be good, especially since some actually mount on the steering column, which is probably great except that this means the whole bowl (of spaghetti) is exposed!
Let's be realistic here, guys and gals. Certain vehicle components need to be in certain locations, with no excuses. I'll get in trouble here, but the engine is always in the front. Sorry Corvairs, I think yours should be, too! The air conditioner should always be under the dash. The pedals won't work very well if they are in the trunk either. There is a perfectly good reason why the other components should be in front of the driver, too. Well, in my humble opinion, this is also where the wiring panel needs to be.
Ok, why? Think of where the big 10 (no longer the big 3) put theirs? Under the dash? Under the hood? Under a seat? In the trunk? Put percentages with those questions and think about it some first. These guys have spent a lot more time engineering the electrical system then ever I can, even though I seem to live this occupation 24/7.
Why? Number one: With the fuse box in the front left corner, the wires are physically shorter. The steering column, dash gauges, the dimmer and headlight switches and other driver controls and switches are right there, too. This means shorter wires. Shorter wires mean several things: Less voltage loss (something know as resistance) which helps provide all the juice your system must muster for the all important and sometimes embarrassing "crank" mode when your high torque, high horsepower, high compression motor says: give all you have or I won't start."
Number two reason: remember that the upholsterer comes after the car is wired and is known for running that extra screw into the transmission case, gas tank, thru a body panel, definitely thru the hidden wire harness, probably thru that big bulky wiring bundle running from the fuse box in the trunk back up front where everything else is located.
I had a long time friend who came to me 15 years ago and insisted he could mount the fuse box in the very back of the car and never have a problem. He obviously survived the upholsterer (or never mentioned it) and several years of reliable service. BUT after a couple years he started with the questions: I can't figure out why my alternator won't charge right. Then it was a light that was dim, or the A/C motor that was getting hot (from low voltage.)
Now, some of these problems may have been generated from a bad ground (which is another book by itself) but they are all compounded by the combination of improperly installed components. Yes, you can get thru one to two years without a problem, unless you want to sell it before then...
[edit] Tech Tip #3 - Glass Fuses
Don’t use glass fuses.
They were replaced by blade fuses 25 years ago for a good reason.
[edit] Tech Tip #4 - Fuse Block Serial No.
Some companies, such as Ron Francis, use a serial number on each fuse box for quick reference. This aids in determining what you have, when you call for help. This particularly applies as designs are changed over time, as companies make improvements and
upgrades to fit the trends, as they come and go.
[edit] Tech Tip #5 - Select-a-CircuitTM Fuses
Copyright Ron Francis Wiring 2003
Ron Francis Wiring first patented the idea of “Select-A-Circuit”TM Fuses in 1996 with the AdvantageTM panel which had 3 Select-A-CircuitTMs. The newer EXPRESSTM and BARE BONZTM models have them in a much more convenient pattern. The EXPRESSTM has 4 and the BARE BONZTM has 2 Select-A-CircuitTM fuses.
The idea it that to ‘select’ which circuit will control the fuse, you need only pull the fuse from the slot and re-insert it over one notch to make the change. This is especially helpful for someone who might want their power windows on the ignition for safety reasons where a friend might want his too be on battery so he could use a remote to lower his windows for access to the car w/o door handles.
The wire itself stays on the same terminal on the fuse block terminal strip which would be marked for P/Ws but the power to the fuse would change. Radios are another item along with some old timers who like to have the fuel pump on a separate battery controlled switch.
Since there are 4 of these fuses, no longer do you ‘splice’ into or over load some other circuit to get the power you need and want. Safety and convenience as all RFW products consider. We make the product work right first and test throughly before you see it on your dealers shelf.
The Select-A-CircuitsTM are available under many part numbers of the BARE BONZTM and EXPRESSTM wiring systems. The Wiring is custom made for GM, Ford and Mopar. We do not use an old GM fuse block and call it revolutionary. Wiring can be a chore or fun and where you actually learn something. Remember: No MORE SPAGHETTI!
[edit] Tech Tip #6 Fuse Types
Mini Fuses are better than ATO-ATC blade fuses because they have silver contacts that keep them from adhering to the similar metal used in the fuse box. The Mini Fuse was first used in 1992. They are available everywhere, including your local food store.
[edit] Tech Tip #7 Fuse Types
As a point of interest, ATO-ATC fuses were first used in late 1978, so this is not new technology. ATO fuses are “open” between the prongs. ATC fuses are “closed” between the prongs. Visually, at first, they look the same, but dirt, water and foreign objects can get in, and some feel, sparks can get out.
[edit] Tech Tip #8 - Fuses
You can have too many fuses. Never fuse one item with more than 1 fuse.
[edit] Tech Tip #9 - Fuses
Using one fuse per item doesn’t include using a maxi-fuse to protect a feed for multiple fuses going to individual items.
[edit] Tech Tip #10 - Fuses
For those who feel they must have some additional protection for heavier circuits, a Magnum fuse is available that can handle 110 or 125 amp fuses. You should put some thought into using these high amp units, though, and consider what they will really be protecting.
[edit] Tech Tip #11 - Fuses
Installing a 60 amp Maxi Fuse in the engine compartment means that you must reduce the load that the fuse can handle. The load may be reduced by as much as 20% if heat is trapped around it. In other words, the right amount of engine compartment heat decreases the rating of a 60 amp fuse to 45 amps!
[edit] Tech Tip #12 - Fuses
If you install a heavy fuse protector on the feed wire to the fuse box, remember that you might have more that 50 amps passing through that wire. Fusing too low will plague you with blown fuses. Fusing at the expected amperage passing through will mean that a small but dangerous load will never blow a fuse. Think twice before fusing many heavy wires.
[edit] Tech Tip #13 - Front Load vs Back Load Fuse Blocks
Pre-wired fuse boxes are one way to simplify a wiring install. But compared to a front loaded panel, where you route the wire to the panel, the installer can stop and start as time permits and not get confused. As it's important to wire a car by circuits, when done this way you can start and stop as necessary, with little confusion. As a note of interest, the Ron Francis fuse box kits are bagged so that you can install one circuit at a time.
[edit] Tech Tip #14 - Front Load vs Back Load Fuse Blocks
Front Load Technology, on a wiring panel or a fuse box, is where there is a terminal block to make your wiring connections. Most aftermarket fuse boxes may have the wires enter the rear, which is fine for a factory car. It is not such a good idea for a vehicle that needs different connections than a similar car would have. Front loading style terminal blocks will also enable the job to be very neat, and perhaps safer. If a wire should need to be replaced for ANY reason, a rear loading installation will require removing the fuse box. When installing such a device, think about how you will access the back of the panel.
[edit] Tech Tip #15 - Terminal Connections
The Ron Francis fuse block have a terminal strip that accepts ring and fork terminals, which are supplied with a special fork. You simply cut the wire to length AFTER you have run it thru the car, the way you want, then strip and terminate. Other styles will load the terminals from the back, where you can't easily see them. If you should have a problem after the installation is completed, this could lead to further complications to sort through.
[edit] Tech Tip #16 - Follow Instructions!
Always follow directions when dealing with anything electronic. And that goes for the basic wiring installation. Look to see the simplicity of those instructions, and if you can understand them. This is especially important if you are a first timer, but the value certainly doesn't stop there-instructions, especially those with tables and charts, can be very helpful.
[edit] Tech Tip #17 - Neutral Safety Switch
Are you using a neutral safety switch? They are standard on new vehicles for a good reason and are required by organizations such as NSRA for Safety Inspection.
[edit] Tech Tip #18 - Routing Wires
When routing your wires, keep them protected on the inside and out. Many times we pay attention to the outside routing more so, because the danger is obvious. Did you know that the inside suffers just as much? Many a wire has fallen prey to the upholsterers screw! Do you have ‘speed bumps’ under your carpet? One way to protect your wires is to use an under-carpet wire channel like the aptly named “Grey Stuff” (GS-10). This flexible channel can be used to route approximately ten wires on the floor under the carpet when in conjunction with thermal shield type materials. Since it is the same thickness as the insulation (or sound proofing), once you lay your carpet over it - it is invisible - and safe!
[edit] Tech Tip #19 - Routing Wires
In reference to routing your wires:
Lower is better! We also do not endorse routing the wires thru the headliner of the vehicle. This is dangerous because of the following issues:
• Chaffing inside roof posts
• Screws or fasteners used to install the headliner
• Very difficult to troubleshoot
• Impossible to trace/replace wires
• Lengthens the wires too much
• Creates voltage drop
Shorter is better!
• Less Resistance
• Less Risk of physical Damage
• Can use smaller wire
• Can make them easier to conceal
[edit] Tech Tip #20 - Wire Types
Cross-link wire is great, but beware of make up of the insulation. The insulation value of TXL is only slightly better than old fashioned primary wire. Use only the GXL and SXL grades, as they have the heavier insulation needed for abrasion and other properties. TXL is used exclusively for EFI, where loads of wire must go into one connector like a computer that requires 100 wires, more or less. In the example of these two wires, they are the same gauge, but differ in insulation. The top one is TXL (thinner), and the bottom one is GXL (thicker). Note that the strands do not change, just the outer jacket.
[edit] Tech Tip #21 - Wire Types
More tips on wire. Shiny wire is cheap wire - a.k.a. “Primary Wire.” Semi Shiny wire is simply a better quality primary wire. Both of the above are PVC and PVC is PVC!! It will burn, drip and can cause a fire to spread. Crosslink tends to be ‘dull’ - not shiny - and somewhat ‘soft’ to the touch. Okay, let’s not go there…
Above right, note the top wire is untouched, regular GXL crosslink. The second wire down is that same piece after we took a torch to it. Note how it simply discolored, but did not burn. The bottom wire is PVC, tortured under the same conditions. Not only did the insulation burn off, it dripped which is a major cause of electrical fires.
[edit] Tech Tip #22 - Wire Guage
The Heat A/C feed wire is protected on some brands with a 40 amp breaker. This means 16 and even 14 gauge wire is too light. Consider 12 or even 10 gauge to be sure.
[edit] Tech Tip #23 - Wire Guage
Did you know....that wire gauges run in ‘reverse’ of logic....the bigger the number, the smaller the wire. Hence, the smaller the number, the bigger the wire.
[edit] Tech Tip #24
More Information on GXL, TXL and the old PVC for those who like ‘charts and numbers to see the difference between each kind of wire:
| | PVC | TXL | GXL
|
| Flame | 3 sec. | 5 sec. | 10 sec.
|
| Pinch | 5 kg. | 5 kg. | 8 kg.
|
| Max. Cont. Temp. | 80 deg. | 135 deg. | 135 deg.
|
| Abrasion | 810 mm. | 400 mm. | 825 mm.
|
| Outside Diameter | 2.04 | 2.34 | 2.34
|
| Wall Thickness | .58 | .40 | .58
|
[edit] Tech Tip #25
COLOR CODING’S JOB, SIMPLY, IS TO MAKE YOUR JOB EASIER. Could you imagine if the caption to this photo was, “Check the voltage on the blue wire…?” This is where Color Coding does it’s job.
[edit] Tech Tip #26
Printed wire is now something of a standard within the aftermarket. Wire printing can be done in several ways; sprayed on in dots, like a dot matrix printer and hot stamp printing. Some have letters, which are larger than others. The whole point of this is easy identification, look at the style you like best, and remember that it is often necessary to read this under the dash-that's when this feature becomes most valuable.
[edit] Tech Tip #27
When using kits designed with GM Color Code installations, this color code will be helpful if you are familiar with that code. Remember too,there are also two or more GM color codes, so check which you are using. If you have a Ford or Mopar engine, the GM code won't be of much help. Unless you are a GM engineer, it really doesn’t matter.
[edit] Tech Tip #28
Above are samples of various crimps.
- is a Good Crimp. It is strong, will hold, and has maximum surface contact for best conductivity.
- has strands out, hence it will have Less voltage and poor conductivity.
- is a low crimp with damaged insulation and poor conductivity.
- is a high crimp and it will not hold!
[edit] Tech Tip #29
On good connections...What does this mean? Check for a physical AND an electrical connection. ‘Pull test’ your crimps before you install them! For those of you who insist on charts and numbers, here is what is recommended:
OEM Terminals must meet these Pull Test Requirements:
| Wire Gauge | Minimum | Maximum
|
| 18 Ga. | 30 lbs. | 50 lbs.
|
| 16 Ga. | 40 lbs. | 60 lbs.
|
| 14 Ga. | 60 lbs. | 80 lbs.
|
| 12 Ga. | 75 lbs. | 95 lbs.
|
| 10 Ga. | 85 lbs. | 105 lbs.
|
| 8 Ga. | 100 lbs. | 120 lbs.
|
And for the rest of us: Give it a good healthy tug, and if it doesn’t come off…
[edit] Tech Tip #30
On the other hand, do not obliterate your terminals by using the wrong tool. There are insulated and UN-insulated terminals. The wrong tool was used in this sample, by using an UN-insulated crimp tool on insulated terminals. Note the damage.
[edit] Tech Tip #31
COMPARISON CHART OF VARIOUS BATTERY CABLES
| FEATURE | RFW LX-CX | AUTO PARTS | WELDING CABLE
|
| YES | NO | NO
|
| Insulation Type | CROSS LINK | PLASTIC | NEOPRENE
|
| Temperature Rating | 125°C (255°F) | 60°C (140°F) | 90°C (195°F)
|
| Flexible? | YES | NO | YES
|
| Molded Die Cast Terminal | YES | NO | NO
|
| Molded in Steel Reinforcing Clip | YES | NO | NO
|
| Resists Corrosion | YES | NO | NO
|
| Non-Drip Insulation under direct short | YES | NO | NO
|
| Crimping tool included | YES | NO | NO
|
| More current carrying capacity | YES | NO | NO
|
| Rear ground cable leg | YES | NO | NO
|
| Performance Rating | #1 | #3 | #2
|
| Best Value | YES | NO | NO
|
[edit] Tech Tip #32
Are you running out of room on your starter solinoid Battery Terminal? We all know that when you wire a vehicle with only what it needs to be driven, you will have a minimum of 4 wires taking up room on that stud. Also, in order to get good surface contact between the ring terminals, you have to ‘nest’ them and spread them out - kind of like a peacock’s tail. This makes it even more difficult to keep the wires neat, safe and hidden. You can solve this problem by adding an insulated power stud (JB-47), with it’s own feed wire to the battery terminal on the solinoid. Then move some of the wires to this remote location and VIOLA!
[edit] Tech Tip #33
If possible, it is always a good idea that the installer be the owner/driver, so that he/she can learn as from the install, and thus if there is trouble down the road, you will be more familiar with how the electrical system is done.
[edit] Tech Tip #34
Remember to not tuck a wire out of the way after you installed it but later decide you probably won't use it. If your memory fails, - “HELLO!” - you'll never remember it is there later on, and if it should become shorted out, you will go crazy locating something you forgot was there.
[edit] Tech Tip #35
You should not have to re-engineer a wiring system installation kit. These kits are designed to be installed simply, and should match the engine and accessories you are using. When using something of a universal type of kit, double check that it has everything you will need for your installation, and the future growth of your system.
[edit] Tech Tip #36
Watch what connectors you use. White connectors with a bunch of round terminals are usually made for appliance purposes, and are not made for automobiles with continuous vibration and movement. When is the last time you saw a dishwasher speeding down the road at 65 mph?
[edit] Tech Tip #37
Always put the battery disconnect on the positive wire. If you have a failure in a ground, the electronics might pick up that ground and damage some expensive equipment. Master disconnects were fine in the negative cable, until electronics came along. Especially ones that remain powered, even when the key is off.
