Designing an Emergency Electrical Circuit
 

Hello Fellow Oogers :

Now that my car is legal to drive and I can begin some shake down cruises ,I have been thinking
about how to make an emergency electrical circuit. Even though this car is all original, I would like to be able to make some small drives, at least, with some degree of certainty that I will get home again. The problem in my mind, is that its running on an original, 90 year old electrical harness! And that has caused me quite a lot of pondering, as to how to keep it reliable and somewhat safe.

The first thing I did, was buy a fire extinguisher; the first I've ever carried in a car. I hate making modifications, but in this case I decided at a minimum I should wire in a fuse which I did. Last week I modified a few sets of points, so that they are easy to swap out without having to pull out the bottom plate. All good, but as I see it, there was still no protection against, say, an internal popout failure, or a major wiring failure or ( gasp) a total melt down of the old harness and everything going up in flames.

I've never been great at electrical but the Model A is simple enough that I figured I should be able to design a totally independant, back up system , that might get me home in the event of some calamnity; and without too much butchery. So here is what I did:

1. Swapped out the original bakelite dist top for a REPO and drilled a hole in the side of it.

2. Cut the brass strapping off one of my modified easily removable points, drilled a hole in it, and joined a new ( pink!!!) wire to it.

3. Threaded this pink wire out the side of the dist, and wrapped it around a second condensor I screwed onto
the outside of the dist, then carried it on to the DS of the coil.

4. Took a second brand new pink wire, and ran it from the PS of the coil to the battery cable at the starter.

Its quite brutal, but even in this brutal state it did function: I disconnected the original wires off the coil, tied on my new pink ones, pulled out my good working points, and dropped my new hot wired ones. Hit the starter ( with ignition key turned off) and of course the car fired and ran just fine.

I'm sure you guys could do a better job of it ( soldering aligator clips onto more correct thick 6 volt wires comes to mind maybe even with an inline fuse) but anyways its a good starting point I think. This should get me home, if the popout were to fail , and ( if I carry a spare good coil ) , should almost certainly guarantee a " limp home" primary circuit in the event of hidden shorts/ melt downs. All without having to cut into my original harness on some dark miserable road side.

For now I am contemplating leaving the hot wired points and spare condensor dangling off the dist just as seen in the last pic, simply as a conversation piece !!! That should raise a few eyebrows , hey? Ha ha! Kev.

Re: Designing an Emergency Electrical Circuit
 

I just took an old primary cable, removed the sheathing and soldered on a clip which can be stuck on a terminal post. It rides around in the back with various other stuff.

Just another way to milk this cow.

Re: Designing an Emergency Electrical Circuit
 

A more simple and effective way!

Re: Designing an Emergency Electrical Circuit
 

ahoogakev, PLEASE DO NOT TAKE THIS IN THE WRONG WAY.........
Would it not be better/safer to replace the old frayed, brittle wires with new wires?
Install a battery shut off switch to kill the power. Remember the "Fire Triangle" you need
Oxygen-Heat-Fuel, you can eliminate the Heat by disconnecting the Battery, new Wiring would help eliminate the fuel and the Oxygen well that can be done as the fire is burning with an extinguisher but leaves a horrible mess. I have a battery cut off switch and a fuse block on my car, I shut down my battery and fuel supply when ever I leave my car. Overkill.... YES But I feel much better doing that. Can a short still occur? Sure, but I will be at/in the car and hopefully be able to prevent my car turning into toast.
Keep your fire extinguisher in a place that is fast and easy to get to, most fires are in the engine compartment and can turn into a roaring blaze in seconds, be careful.
As I said "replace the wiring" you will sleep better.

Re: Designing an Emergency Electrical Circuit
 

https://i.imgur.com/Qvlzxto.jpg?1

Fire?no..fuse blows :) modern solution to old problem..

Re: Designing an Emergency Electrical Circuit
 

Model A Ford's have survived for years with the original design wiring. Those who go in for judging spend thousands of dollars to rebuild heir cars searching for the big point score and all use new wiring harnesses to the original design. Put in new harnesses on your car. Put in a fuse if you wish and a safety switch but don't loose sight of what a Model A is. Bill

Re: Designing an Emergency Electrical Circuit
 

I put in a fuse block with fuses for the brake lights, turn signals, alternator, headlights, horn and main fuse. I wired it according to the article in the "Model A News" in 2018. I mounted the fuse block on the firewall. (see attachment)

Re: Designing an Emergency Electrical Circuit
 

When my A was new to me it was 40 years old, wanting to detail the engine I was at a car wash when all of a sodden the smoke leaked out. I disconnect the battery and after some time I got brave and reconnected the battery took it home parking it until a new wiring could be installed.

Re: Designing an Emergency Electrical Circuit
 

Model A Fords have been modified and improved since 1928. To outfit a model a ford to compete with today's traffic,to make the original components relevant is my choice.A modern electrical system not only improves performance but reliability.

Re: Designing an Emergency Electrical Circuit
 

Thank you all for your thoughts / suggestions; to me it just comes down to ones personal choice of how much risk and how much reduction in risk one wants to take.I doubt many out there are trying to run on original wiring but just in case I thought I'd post my method I think gives me a fighting chance to run wth it AND also ,a quick easy way to get home in case of popout / popout wire / dist wire / points/ or condensor failure. A battery quick disconnect switch sounds good too, I may or may not put one on this car but I am pretty sure my next A ( a true driver car) will have one.Kev

Re: Designing an Emergency Electrical Circuit
 

Thanks Kev, I think we all appreciate seeing new ideas to keep our cars on the road. You sir are absolutely correct, these are our cars and we all have our own ideas of what we want to do to them. Be it building a beautiful points car that is driven or trailered to a show or a car with patina that we drive as much as we can. The end result is the same we all love the hobby. Thank you for sharing.

Re: Designing an Emergency Electrical Circuit
 

Hmmm, foolish me. I thought this was about overcoming an 'emergency' with a quick snap on primary cable. At least I thought thats what the title mentioned.

Re: Designing an Emergency Electrical Circuit
 

Hey Patrick; Well maybe it is I don't know, for one thing I have have never been great at memorizing all the correct terms for anything - so I don't know what you mean by primary cable - I think one side of a coil is called primary? But then I think I read the BIG coil wire to the spark plugs is the primary ? ( maybe its the secondary) So all the above confusion is why I just called it " emergency circuit" - I meant a circuit that will power my points and my coil , and THAT should get me home in case of quite a few emergency failures ( or failures that become emergencies maybe a better way to say it ) Theres probably a better way to do it but this will work for me and if it helps spur anyone else to create a limp home wiring thing well great , Kev

Re: Designing an Emergency Electrical Circuit
 

That response was kinda tongue-in-cheek and not directed toward you. I thought you originally were referring to a simple wire that could be kept in the car and used for an 'emergency' like the car not starting because of an electrical issue at some inopportune time.

Many of these posts get carried into different directions as this one seemed to.

Ignition circuits.

Primary is the low voltage section. Battery voltage from the terminal box to the coil to the switch to the distributor [ points/condenser]

Secondary is the high voltage section. High voltage from coil thru to the distributor high voltage parts and then to the sparklers.

Re: Designing an Emergency Electrical Circuit
 

Seems like Kev is ahead of us, he doesn't even have to open his tool box, he is pre wired and with a clip of a clip he is up and running. Great to have new ideas.........

Re: Designing an Emergency Electrical Circuit
 

Mr PalAl, you have figured out a great Truth about me, I love keeping things simple with nice little easy solutions always at the ready - but the trouble is I so often get wrapped up in circles going to huge lengths in my mind trying to get there !!!ah ahaha Kev

Re: Designing an Emergency Electrical Circuit
 

Thanks Patrick; that sounds correct and vaguely familiar but I hope you realize, its gonna be cleared right out of my head again as soon as the SomeTimers kicks in ...and it kicks in a lot these days ! Kev

Re: Designing an Emergency Electrical Circuit
 

I can certainly relate ! :D

Re: Designing an Emergency Electrical Circuit
 

I maybe the oddball out there, but my daily driver still has the original wiring harness. I inspected it thoroughly before I put her on the road and recheck things now and again. I've had very few problems. I did install a battery shutoff, a main fuse at the starter, and a second fuse block under the dash. Any accessories I have added (cabin lights, USB charger, etc...) go through the fuse block.

Keep in mind, if you do install a new wiring harness, I have heard many complaints about the connector for the light switch at the bottom of the steering column. Many people will remove that connector from the new harness and solder in the original connector.

Good luck,

Ken

Re: Designing an Emergency Electrical Circuit
 

Let’s just reinvent the wheel.