Bob, several posts here had a defective product like regulator, etc problem. This is the offshore garbage. I am fairly certain it was Ron Francis maybe 45 years ago, had to recall all the fuse boxes he had sold in his kits. Those old glass fuse holding pieces were poorly riveted to the wire connection points, which got loose and caused resistance/heat/odor. The more times it got hot, the looser the rivet got. Never assume a "new" part is correctly made. Never toss a good quality USA older switch that can be disassembled/inspected/ cleaned, in favor of a new switch made in a unknown origin that just plain looks iffy. Use fuse panels/switches that pass the visual test for such crappy designed connections. Use best quality switches and even NOS regulators etc. Never put too many circuits running through an ignition switch, as it can melt the terminals due to overloads Use higher quality kill switches that have proper sized heavy duty terminal studs. Basically fires start or wire "smells" come from two sources; One is wires rubbing and chafing through. That is the builders fault entirely. The other cause is resistance; either from loose connections posted above, or underrated switches or wire sizes on unfused circuits...any thing that causes resistance has heat as a by-product. That is physics.
Fusible link on my '63 Safari fell off my alternator at the end of a 600 mile trip due to crappy spade connector. Incinerated entire harness, but once the smoke cleared, I was able to drive the car on battery power after it caught fire at a gas station (never shut it off!). Drove 20 miles to my garage. When I put it in 'R' and the b/u lights came on the battery finally gave out & the car died on the apron to the bay. Electrical is the most neglected system on most vehicles and the least respected. If you are not the original owner, if you dig deep into your car's system I would be surprised if you do not find places where previous owners have spliced and taped. See it all the time. The insulation becomes brittle over the years regardless of care. Replace it all with a new harness. It is not that difficult of a job, and you will never have to worry about it.
I had a Triumph for a little while last year, with the Lucas electrics. I didn't find anything scary about it. I expect some guys have problems with it, because they don't take the time to understand how they are designed to work? I don't know. But as to how to put the smoke back in the wires...first, you have to buy the right kind of smoke.
Why do the British drink warm beer? Lucas builds their refrigerators too. Sorry couldn't resist that old joke. -Dave
Whoever came up with that must be as rich as Solomon, 'cause Lucas stuff is always running out of it's factory smoke!
Mine was in the garage when I tried to start it and it caught fire. A decorative cap nut the P/O installed vibrated loose and wedged between the pos cable and the starter housing...no way to get to the battery under the seat w/o pushing the car out of the garage to open the pass door. Luckily, just some cable damage as the temp fuel line was run right next to the cable and didn't burn through. When I rewired, I installed a cut off switch in the seat riser near the battery. On a different note, I just rewired my small diesel powered sailboat, and in doing research for that I was convinced to use a fuse on the battery (or near,I was able to use a small enough amp fuse that the battery holder works fine ) for the starting circuit as well as the rest. This is the fuse holder I used : https://www.bluesea.com/products/5191/MRBF_Terminal_Fuse_Block_-_30_to_300A Yes it's for a marine battery with the other kind of terminals, but if I used a different fuse holder on my car battery cables, I wouldn't have had the fire Here is the article that convinced me : http://www.pbase.com/mainecruising/battery_fusing Lot's of other good stuff on that site....proper crimping,how to make battery cables etc
I'm usually pretty careful about replacing old wires, but it's not always the wiring to blame. A couple of weeks ago I was starting the car in the morning to go to a show. As I cranked, smoke started rising from under the hood. I grabbed the extinguisher and popped the hood. Turns out that a rubber grommet through the firewall had failed over time allowing the coil wire to chafe and short against the firewall. Once the first wire melted, it caused a chain-reaction that melted the convertible top wire (which is direct to battery with an old circuit breaker). I looked in horror as the sparks arced and the wires glowed and I didn't have a wrench handy to disconnect the battery. I grabbed the arcing wires and pulled on them a bit, defeating the short circuit and I stopped a full fire from starting. So now, after replacing the grommet and melted wires, I'm going to put a master kill switch to be sure that any future shorts can be shut down at the flip of a switch instead of looking for a 9/16" wrench in a panic.
I bought an old motorhome years ago, spent a couple months fixing it up for our big summer vacation drive to Colorado. Got the A/C working, put in a big stereo, got the 12V fridge working, stocked it with drinks and headed out. Halfway across Nevada the temperature cracked triple digits so on went the A/C. Got it made, tunes, A/C, cold drinks...until it overheated the non-protected alternator charge wire, filing the cab with smoke and turning that harness into crispy bacon. No flames luckily. I managed to separate all the crispy wire and redo it with lamp cord and limp back on the road, sans A/C, sans cold drinks, sans radio...
All good experiences----I have a all power off switch located between seat & back cushion you can flip with fingertips for fast action. Seeing a person along the road with hood up & smoke billowing out standing helplessly by, I carry a med. size bolt cutter in my family car & my truck for an immediate response for cutting either the positive lead on battery OR the ground lead----Either will cease all power thats feeding the problem.-----Also, fire extinguishers.-----Don
I had my '39 coupe for about two months when i finally got the brakes all sorted out and rebuilt. I could now drive around and actually stop so of course it was time to go for a test drive. Its about 9 pm on a nice September night. I ask my girlfriend if she wants to go for a spin around the block, sure she says. We go down the street, get to the dead end and turn back around. We're heading back to my shop and i decided to keep driving past it and go to the end of the street, then turn around and come back. I get to the end and turn around, drive about 50 more feet and all the sudden i can see sparks lighting up under my dash! Next i start to see smoke coming into the cabin. At this point i pull over immediately, shut the engine off, and we both jump out of the car. I pull out my phone to use the flashlight and can see that the bare horn wire is rubbing on the water temp. sensor wire. That's what was causing the sparks and melting the rubber grommet in the fire wall, hence the smoke. Thankfully after i shut off the car and separated the wires to make sure they weren't touching anymore everything was normal again. I was able to drive the 500 ft back down the street and into the shop. Bottom line is that the wiring is as important as brakes, if it looks old and crappy change it. I'm very glad i re-wired the entire car. I can now cruise around without worrying about sparks and smoke. -Chris
^^^^^ Yup Couldn't agree more. Just finished getting the new motor put in my 51 Chevy a few weeks ago after the old small block gave up the ghost. I knew I needed to rewire the car they day I got it, but I was having to much fun driving it to tear it apart and do it. Got the new motor in hit the starter button, fired right up and ran for about 30 seconds. Then shut right off. that's when I saw the smoke and sparks from under the dash. The insulation was all gone from the wires to the Amp gauge and shorting on a the Walton fab pedal under the dash. That got all the wires in a taped up mess nice and hot and started smoking the insulation off of them. Got the battery disconnected and it calmed down and fizzled out. Should have done it a long time ago, at least I already had already bought a new harness to rewire it with.
I was working on the wiring on my '46 WC-26. I hooked up something wrong. Flipped the switch and massive smoke poured from under the dash. Killed the system and found the problem. The look of horror on my friend's face as I re-energized the system and told the damn thing to burn was priceless.
Fuses are important but they need to be in the right location, as close to the battery as possible. When I worked at a Ford dealer I got all of the wiring problems. One customer had a fire in a 75 Mercury Marquis that ruined the wiring harness. The owner, who was a truck driver, was claiming it was a factory defect. When I removed the harness I found a wire put through a hole in the fire wall that was wrapped around the harness and connected to the battery. It went to his aftermarket CB radio. The wire was fused but the fuse was at the radio instead of the battery. When it shorted out in the unprotected hole in the firewall, the wire got hot and melted into the harness shorting wires in the harness together. Another owner, also a truck driver brought his new 79 pickup in after having it for a weekend with the tail light fuse blowing when the lights were turned on. It had been rustproofed so the service manager suspected a wire got pinched when the tail lights were installed. When that wasn't it, they brought it to me. The first thing I noticed was an aftermarket sound system had been installed which was common as the Ford truck radios were junk. I removed the radio and found that they had connected the positive and ground to the Ford harness. One wire in that harness is power for the radio and the other is power for the light in the radio. He had the radio ground connected to the light circuit. Ford truck dashboards were steel so the radios were grounded by the mounting as was the aftermarket radio so it grounded the dash lights which were on the same circuit as the tail lights. These and other incidents are why I say the second scariest thing in the world is a truck driver with tools.
Any electrical system that is properly designed has two main things taken into consideration during the design process; getting power to where it's needed, and managing the heat generated. http://www.jalopyjournal.com/forum/threads/wiring-101.843579/ If you feel the need to install a master cut-off switch or giant fuses on the battery leads on a street car to prevent electrical fires, then the design has failed
That is one of the very basic questions I'd really like to understand, there are volts and amps running through the wires at the same time. I guess you can measure one with an Amp gauge and others with a volt meter. What happens if there is NO GAUGE installed? Bob
Volts don't run thru wires. Amps is a measure of the amount of electricity. Voltage is the power to move the electricity. Think of a water hose. Amps is the amount of water. Voltage is the pressure pushing the water out of the hose. Almost block off a water hose. You have high water pressure (high voltage) but only a tiny stream of water (low amps)
Electricity doesn't care if you are measuring it, or not. It will work just fine either way. Please excuse the spelling. I posted this with my phone.
You do not need a gauge if that is what the question is? Just a crude, easy difference in amp versus volt gauge: -an amp gauge was made in two different types. The older technology had the actual heavy wire that feeds the battery (charging/discharging), running right through the gauge. The bad about these, is that you need that heavy stiff wire running through the firewall and under the dash. That leaves the possibility of that heavy wire getting chafed and shorted out, and because it is a stiff wire, it will chafe through the insulation much easier than a soft flexible wire. And because it is a heavy wire, it can supply more amps if shorted, and it can get generate a lot more heat (if shorted). -the newer technology amp gauge is called a shunt type. It uses very thin wires in comparision, so it is cheaper for car companies to use, as it's less copper. - the voltmeter is likely the best choice. It only needs one wire from the "key-on". And the gauge is grounded on the other terminal. It can be a very tiny wire, protected with a very low amp fuse. The voltmeter can provide more info on what is going on. If the gauge shows much lower than normal when you only turn the key "on", but then it climbs back up to 14 when running, that is a sign that the battery was low; either it's going bad, or something was drawing the battery down when parked. another thing, is if the volts do not come up to 14 like it was doing, that could mean the generator/regulator needs attention, or it could indicate a failing battery also. One good thing about an idiot light, is that you will spot it instantly if you were on a long sleepy trip, and the generator stops charging. It might have taken much longer to spot a gauge reading low. You can run both if you choose. .
It's electricity, it follows the laws. You can't make it do anything it's not supposed to do. It's not like people who need the presence of traffic cameras to behave properly. Electrical fires happen because electricity is going exactly what it's supposed to and following its laws but the people didn't. If your mind could approach electricity as a relationship between electricity and yourself, you would say "ok we aren't going to hurt each other, right? " and the electricity will say "I'm going to follow the law no matter what, as long as you do your part there won't be any problems" Electrical Fires are caused by heat, combustion range heat generated from electricity is due to a few things but mostly friction. Too much electricity (amps) rushing thru too small of a pathway. Think of an electrical fire as a traffic jam but the traffic didn't stop or slow down, every car just ran Into and plowed into the obstruction. Only the cars are the electricity.
At the risk of minimalizing a serious issue, I feel that the basics are your best friend. I almost get angry at the discussion of relays. Seems like the relay is the new millenium "must have" in a build. Why? How come cars from the 30s are still running around WITHOUT relays? Old headlight switches are their own, horns need em, starters have em, and let me think, nope. No others involved yet today we need to relay the info to the use of a relay to activate the relay for the muffler bearings in the connuter valve. Basics. Less is more. Check load ratings and amp draw, build as needed. Another area that's easy to forget, GROUND CONNECTIONS. Bare metal to bare metal where the starter mounts. A little spray lube will keep it clean for decades. Star washers for ground connections. Ground straps from the engine to body to frame helps keep it all going "back where it came from" and allows components to run cooler. The less circuits the better. Grommets. Solder and shrink tube vs crimp connectors. Crimp connectors are best suited to roadside fixes rather than a permanent installation. Maybe a component you might not keep, but even then a simple clip of the solder joint when you take it out. Electrical fires are not fun and should guide one to a safe system. Lots of good engineering out there to learn from. In our carb and points world simple should be easy.
Aah, fun with electrical theory------ Ammeters are good because they show which way the current is flowing. To the left (discharge) means out of the battery and to the right (charge) means into the battery. This is why a lot of ammeters don't even have numbers on the gauge, the important part is which way the current is flowing. I'm with Highlander on the relay issue. They aren't necessary unless your wires and switches are too small to handle a load. I've read threads here where guys are installing relays to feed relays. Just adding another potential source of failure.
33V, that is profound. I specialize in fuel related fires but this thread has me reflecting on years of hack lamp cord wiring without only occasional smoke. At least I use fuses now. Good thread.
I really like Bob, I want to help him and The standards of electricity is a hard concept for him to get ahold of. Use the water anology and he gets lost because electricity and water don't mix. I think once he can mentaly visualize electricity and how it relates then the standards will start to click.
When I was 17 I rewired my ot dodge coronet. At the time I didn't think the firewall grommet was needed (17 and stupid). Long story short, I was wiring the car again about 3 months later. Ever since then I have had a healthy fear and respect of electricity and fire, but I think that is what makes me really good at wiring now.
I think relays need to be on a case by case study. A blanket statement that they aren't necessary is not any more wrong than a shotgun approach that everything needs a relay. Here's an off topic example with an on topic example following. Let's say you scored some power seats from a car that utilized a body control module to move them. The seat switches communicate with the BCM and the BCM sends the power to the correct seat motors. In order to get those seats to work and not burn them up you'll need to build a relay board to replace the BCM. The switches will communicate aka trigger the relays and the relays will send power to the seat motors. Or how about sequential tailights? When you want to have old antiquated switches operate the corresponding components. You'll be far ahead to have those switches operate peapea relays. How about where localized space is at a primo but it's limited. A relay can eliminate space or confine problems by use of smaller guage wires and switches. You add the relays where the space is cheaper. It makes the electrical aspect more complicated but everything is a trade off or compromise.
You're both right. If you are adding modern stuff to an old car, then relays are a good idea. If you are just using old stuff, not necessary. Please excuse the spelling. I posted this with my phone.
I'm using a 46-48 Ford car column in mine. Those old generic rectangle box ignition switches seem a bit "not made right". That exact switch is also stock in some other brand cars I have here, and I always take them apart to clean the contacts. Each and every one has a brass plate that makes contact with 3 brass dots in a bakelite strip. In every one, when it is in the on position, the old wear pattern shows it is not quite lined up with one of the dots. It's sitting on the edge of the dot, and without trying everything I could dream up to make it align, I let it be. It works fine so far, but for that reason of less than perfect contact, I only run the distributor wire and dash gauges only. Nothing else at all. I could have used a relay for heater, and separate defroster blowers, signals, but I just ran those as not "Key-on". I have dozens of the Bosch relays here, but want it simple, with minimal wires to clutter.
Here's my take. Race car, simple circuits, less wire, relays can safely run things like electric fan/water pump sytems. Maybe you have a heavy amp draw on a high capacity fuel pump, same same. Traditional hot rod, flathead or hot banger, lights, maybe a heater at best, possible radio. The headlight switch has it's own gig within, maybe even the direct connections at the base of the column. Radio? If it's not the size of a toaster and runs on tubes you'd be more than safe just wiring it in. Heater motors were usually low draw but also had resistance circuits in their switches for high and low speeds. if you swapped up to 12 volts you might want bigger wires and a 12V resistor switch for high/low operation. Back to basics, old 6V systems tend to be heavy on amps and were designed for it. Newer 12V systems that we tend to wire up ourselves, pay attention to loads. Adding a 300 watt amp for your tunes? Be sure to wire it direct with the proper size cables and soldered connectors as well as enough air space to keep it cool. And as mentioned above, when using a master disconnect make it a big one. Amps vs Volts, you want big amp ratings on a master switch. I've seen them rated 250V but only 60 amps. Back to excess relay use, when the whole boom in bracket racing took off in the 90s it seemed every component on a purpose built car was relayed. Much like the all "naked" wiring harness with a zip tie every 2", shortly after we started seeing that in street cars. I've heard "...so you can see the wires if something stops working and...", which means they really don't know why it was done. Weight and simplicity is about the only reason. How many times have any of you found a single wire that was bad within? In a lifetime of cars, not once for me. Connections, joints, components, switches, yes but a wire, never. Wires get cut, punctured or burned through, old cloth wires lose their skins, rodents eat the new soy based coverings. Any one of those instances can be seen in most cases. The use of relays is pretty easy to determine, and yes, running a new hi-tech system of power seats and such, maybe so. Not every car, every time, every accessory, every circuit. Like Scotty said to Kirk, "The more complicated they make the plumbing, the easier it is to stop up the drain."
I also agree with Highlander on relays. Starter and horn relays, that was usually it for relays until the late 50s. This was generally true until the advent of alternators, at which point relays came into more use because you now had enough power available to install many more electrical accessories and overloading of ignition switches (or other switches) became a very real possibility. For us (replacing or modifying wiring harnesses), relay use was popularized by the aftermarket but what they failed to tell us is this was primarily to hide the inadequacies of the product they were selling us. Got dim headlights? Use a relay, it's magically fixed!... When the base problem is too-small wire somewhere in the harness and voltage drop is allowed to get too high; poor harness design... This design flaw is encouraged by the OEM manufacturers who did the much same thing, but not quite for all the same reasons. Look under the hood or dash of any late-model and relays will be everywhere, but that is because these days most electrical loads are switched via microprocessors rather than mechanical switches; solid-state switches are difficult (and expensive) to build with the capability for switching high currents (anything over a few amps), so relays are the (cheap) answer. Relays have their place, but are used too often as 'fixes' for poor design. And don't even get me started on what the aftermarket sells; off-shore junk with 'ratings' that bear no resemblance to reality. Keep in mind that there are NO, NONE, ZERO 1/4" spade-connect plug-in relays with legitimate ratings beyond 30 amps continuous-duty because the connector that fits these is only rated that high. Post 22 was probably a prime example if this... Using QUALITY parts is critical; Bosch is good, or if you need something larger than what they have, look for UL-listed relays (McMaster-Carr is a good source). Avoid no-name relays with ink-stamped 'ratings' like the plague... Relays can be wonderful things; if you get into multi-pole, time-delay, and latching relays and/or limit switches, there's almost no limit to the interesting circuits you can design. I did a 'turn signal module' on a motorcycle with single-filament front running lights and two rear brake lights (no dedicated turn lights) using relays. Soldering vs crimping.... always a contentious subject. I don't like solder, for me it's crimp-only except in very specific cases. Solder has two issues; one, solder defeats one of the main reasons copper is used for wire. Copper is very malleable (able to bend without breaking) and solder joints will break if bent more than a few times. Yes, proper strain relief will fix that, but shrink tube may not always do the job. Solder joints also don't like vibration. Two, a solder joint will fail much faster under heating conditions compared to a mechanical crimp. Got a soldered-on ring connector and the nut holding it loosens? The connector can heat up, the solder runs out (making the electrical connection even worse, more heat), and now the wire can come loose and short to something else. With possible catastrophic results... A mechanical crimp won't do this; it will still heat up, and probably burn several inches of insulation off the wire, but the wire will stay in place. Of course, a crimp must be done properly, so having the right crimp tool is critical. Soldered field connections have been illegal in the electrical industry for over 50 years for just this reason....
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