I have a 27 Center Door Sedan. A previous owner had installed a coil and distributor. He also changed the wiring so that the car is reverse polarity. Quite frankly as an electrician it makes me cringe. My plans for the car is to make it a reliable driver. So what have any of you installed on your cars to make them electrically reliable?
If your car is a center door it is not a 27, but that's ok. Minor detail ;)
I am too new to answer your question though. My Model A experience made me think a T must be positive ground too. I reversed the cables on the one I bought thinking the previous owner had it wrong, and it still ran fine. I now know better and I'm hoping no damage was done.
Changing back to the original ignition system would make the car much more reliable. The car as Ford built it can drive anywhere even if the entire generator and battery system fail.
There seems to be some Universal Law that at some time in its life, every old car will pass through the hands of someone who shouldn't be allowed sharp tools, let alone touch wiring.
There's no reason to have positive earth with a distributor and coil - and no reason to change it if it has. Reliability comes from the quality of the wiring - routing, right cable, connectors etc.
I have a 'stock' car - Royce would approve (I hope). But a good distributor and coil will be just as good.
However, if you want to follow Royce's advice, you can do no better than to buy a set of looms from one of the main suppliers. They are not expensive or complicated, they are well made, and they have the right materials and connectors.
But you will also need a coil box, 4 GOOD coils, a timer AND ideally a working magneto. Check this first. 12v DC can be almost as good, 6vDC is not.
The alternative is to bring the distributor installation and wiring up to your standards.
Electrically reliable means:
- a wiring harness in good condition
- every connection bright and tight
- ignition switch repaired/restored
- properly rebuilt generator if equipped
- cutout of your choice but not a mechanical one
- properly sized battery cables if starter equipped
- rebuilt/restored starter foot switch if starter equipped
- a good battery and coat the terminals and cable ends with Vaseline.
- an accurate ammeter
- properly wired front and rear (if equipped) lighting
If you wish to keep the dizzy then skip the following:
- a coilbox rebuild
- a good timer harness
- a good timer
- center the timing cover
- remove the slop out of the spark advance rods
- rebuild the coils
- properly set spark timing
You can do most of this work yourself. The genny and starter, if needed, have to be rebuilt by someone who knows what they're doing and will explain their work to you in detail BEFORE you ship them out. You can learn to rebuild coils but if you don't have a way to test them properly it's better to buy them from someone who can test them PROPERLY.
If you're not willing to undertake all of the above items, you will have problems.
Here's the rub, I've been told it's a good idea not to switch to the magneto if I have a reverse polarity system. Also a fellow member saw a picture of my generator and said replace it as it is a fire hazard. Everyone I talked to at the Hershey swap meet said rewire it and if you could see the wiring under my car, you'd understand why I'd want to redo it. Since I don't care if it's show quality and only want to drive my car on nice Saturdays I just want a simple, low maintenance, reliable system.
Just a picture of what I have top side.
Tom, the main thing is not to let the smoke out of the wires. Every time that happens with me, something goes wrong. I let my son do all the wiring hookups. He's been to school on smoke and wires.
Allan from down under.
Your car looks like a 27. The firewall looks like 27, but I don't think it's a centerdoor. The ignition system is not Ford. It is a distributor, so don't switch to magneto regardless if it has reverse polarity, In fact I would even recommend you remove the wire between the switch and the magneto so it can't be switched.
The distributor is made to run on DC and the magneto puts out variable voltage AC. Most times the car was switched to a distributor because the magneto doesn't work. Or the owner doesn't understand the coils and timer so switches. Anyway, if it runs as is, unless you want to there is no need to switch to coils and timer. Just be prepared with spare points condenser, rotor and cap because you could have a problem while driving and need the parts to get it running again.
Tom, magneto operation of the car has nothing to do with the whether the T is positive or negative ground. The magneto provides AC current for the coils/lighting. The generator, if so equipped, is used to charge the battery and na'er the two shall meet or you will have a real problem.
Norm, car is a 27, included picture, can you id the model? For lack of anything better I've been calling it a 4 door sedan.
Anyway, regarding spare points, condenser, rotor and cap, I can't identify what I have on the engine. I know the points are part of the distributor and I don't see any way to remove them. Also, look at that contraption that I assume is the generator! My thought is to go to a 6 volt alternator, new wiring harness, and either an electronic distributor, (I think I saw one in Texas Ts) or I've heard about an electronic box that simulates the 4 coils using an original timer.
A picture is worth a thousand words. I suppose your original description was correct......., in a way. Yes you have doors in the center of the body but you have two more in front of those, so..... your car is a 4 door sedan. You got the year right in the original post.
I'm still too new to T's to be able to comment about stock ignition vs a dizzy, but I suspect close to a billion cars over the last century have been built with distributor ignition of various kinds such as yours so it should be possible to make it reliable. From the pic of your engine my biggest concern is how close the spark plug wires are to the exhaust manifold. I would try to route them so they keep some distance from that heat source.
As to polarity, lets make sure we all know how yours is wired. Which post, + or - is grounded? as I stated before, Fords from the Model A until the introduction of 12 volts used positive ground so a distributor can work either way.
As already stated, the beauty of the stock T ignition is that it is not dependent on the battery or generator. Once running you could toss both and still (before dark preferably) get home.
The home made device that is sitting to the front and on top of the generator is scary to me. The yellow/black tracer wire that connects to it is HOT ALL THE TIME and runs from there through the ammeter and then straight to the battery HOT so be careful not to touch any part of that thing. I would get rid of it and get a properly rebuilt generator on the car. With that "gizmo" thingee on the generator I would not leave the battery connected but I also don't recommend you installing a battery master disconnect switch since those are problems too. Rewiring the car is the first order of business. Next find out if the magneto is working or not and THEN decide whether to keep the distributor or change the car back to coil per cylinder ignition which incidentally is what modern cars now use again. Nothing in your T needs 750+ watts of power that an alternator brings with it. Find out the condition of your generator before you replace it but do NOT trust modern generator shops at all since they typically don't have anyone qualified to know how an adjustable 3rd brush generator even works. Before rushing headlong into replacing things, find out the condition of things first and then put together a plan. Find someone local or online and work with that one person to resolve your car's electrical system issues or you will be chasing all over the place if you instead try to form a committee here or at your end since everyone will be giving you advice and often it will conflict. In general if you move the car back to what was original then you will find way more cars and people that can help you but pick out one person, hopefully local, to guide you.
Ford's name for that kind of car is Fordor. They called the two-door version a Tudor.
Opinions vary on the question of whether to use a disturbutor or the Ford ignition system. The divergence of opinions is due to varying philosophical, historical, aesthetic, and practical considerations, as well as knowledge and familiarity.
In the philosophical/historical/aesthetic realm, some see the Ford system as the heart and/or soul of the Model T, and so-called "upgrades" make the car less than a real Model T. These folks would say if you want a dizzy you might as well get a Durant or a Studebaker. Not that those are bad cars, they're just not Model T's. Part of the Model T's charm for this camp is its uniqueness. There's no other car like it. Others don't give a hoot about all that. They just want a reliable car, and are willing to make any alterations they think will advance that cause, which brings us to practicality.
In that realm there are also different opinions. There are persistent superstitions, based mostly on unfamiliarity, that cause people to make changes that are superfluous or even counterproductive. A couple of examples are the notion that a twelve volt conversion is necessary for ease of starting, and that a water pump is the proper cure for overheating. Research, in the form of practical experience and studying the experience of others, shows that both these assumptions are bogus. The question of ignition features is less clear cut. On the practical level, either system can be made reliable. But the Ford system has one distinct advantage. If a coil goes south, you can still make it home on three cylinders. If the coil or capacitor in a distributor system fails, you'd better be carrying spares.
My own inclination, based on the philosophical/historical/aesthetic considerations I described, it to stick with the original Ford plan in most cases. It happens that it's usually also the practical choice. The one drawback I see is the possible expense of converting an altered Model T back to its original state.
No doubt I'll be accused of beating a dead horse, and the original question wasn't about this particular aspect of Model T alterations, but here's my take on converting to twelve volts to facilitate starting: https://www.youtube.com/watch?v=b5ycpdfIjDo
How fast does a T need to spin for starting?
Like Steve says, and having owned and driven stock Model T's and Model A's on old car tours over the years, I have learned the following: The stock Model T will get you off the road safely and even home on 3 good coils. The stock Model A can have the distributor capacitor fail at any time, leaving you stuck with out spares. Special note, the Model A distributor is a lot easier to get to than aftermarket Model T distributor.
Here is a wiring chart, if no one has posted it yet. Jim Patrick
First let me say thanks to all for responding, and also I am extremely jealous of that guy in Steve's youtube video and how easily his car started. Gives me something to aspire to!
So after a lot of reading I have some questions I hope someone can answer.
Question 1: Can anyone identify that "thing" that sits on top of my generator? And what is it's purpose? I've heard scary and fire hazard associated with it. I don't feel warm and fuzzy with it and am thinking of ditching it when I rewire the car. (Yes, I hate the fact it's wired like a Model A, I want the negative to frame ground again, and no the reverse polarity was not my doing.)
Question 2: Where can one get spare parts (rotor, points) for an Atwater Kent type LA? After reading today, I'm seriously considering ditching that too and getting back to original coils which I don't have. Which brings me to....
Question 3: I know the coil box didn't mount on the fire wall on a 27, so where did it mount? Does anyone have any pictures?
That's it for now, I'm on a steep learning curve so please have pity for a poor newb! Thanks in advance for the help!
That thing is a replacement cutout for some other brand of car adapted to fit on a T generator. You can buy a Fun Projects cutout from Fun Projects or from any of the T part vendors.
Ok Royce, at the risk of really sounding stupid, what is the purpose of the cut out? How does it work?
Many liken the cutout to a voltage regulator but it's much simpler than that and in no way regulates system voltage. At lower engine speeds where the generator output falls below battery voltage it simply opens the circuit to prevent discharge of the battery through the generator.
System voltage is regulated by the position of the so called "third brush". Back in the day setting the third brush on your daily driven T was based on a drivers estimate of how the car would be used and even the season and how much one expected to use the headlights.
Thanks Gary, now I understand it's function, not so sure I understand how it does it. Guess I need to read up on the generator and the "third brush". Now I have another question. When I rewire this car to have the normal polarity Henry intended it to have, what do I have to do to both the generator and the starter motor to insure the polarity matches? I'm assuming being DC whomever rewired this car to reverse polarity also changed the polarity on both of them.
I'm also awaiting answers to the questions of spare parts for an Atwater Kent distributor and if anyone out there has pictures of a 27 with the coil box mounted in it's original position.
You're welcome Tom. After I posted my answer, I realized I could have just called the cutout an electro/mechanical diode.
I would just use the wiring diagram posted above to verify the wiring connections. The starter is of course case grounded to the transmission cover, a.k.a. "hogshead" so the only other connection is the cable which comes from the starter switch.
The ignition when running on magneto is indifferent to polarity.
I would suspect that if the prior owner reversed polarity it was just done by reversing the battery terminals. At that point the very simple circuitry of the model T just goes from power side switched to ground side switched. So just verify the connections at the generator and you should be fine.
Tom, here's a 1926 engine showing where the 26-27 coil box is located. As you can see, it's equipped with correct NOS dust.
When I had inherited dad's car I had a rat's nest to go threw.
Finally got it all sorted out.
Makes a big difference .
Steve, love the NOS dust, looks like it was near a cement mixer! Thanks for the picture. Since a previous owner converted this to coil/distributor I don't have the coils or box. I'm not to worried about obtaining them, however will I have trouble finding the mounts?
George, like you I inherited my Dad's car. It was an owner previous to him that bastardized the electrical system, reversing the polarity, attempting to add blinkers and brake lights. My intent is to strip it all and rewire it back to the basics and eventually get those wireless LED turn signals for safety while driving. Along the way I've gotten to the point where I'm concerned about the distributor. It has a lot of play and it doesn't seem like the parts for it are to readily available.
At the risk of reigniting an old argument from previous forums, how do you guys feel about the true-fire electronic ignition that simulates the coil box?
Another wiring Image could help.
There's a 99.44% chance that any 26-27 coil box you find will have the mounting brackets attached. They're riveted on.
Thanks Steve! Been watching you on your youtube videos! Any chance I can convince you to relocate to northeastern Pennsylvania? Anyway, what is your view on the true-fire ignition? Would that run on the magneto or does that require strictly DC voltage?
Hummm? When Henry started making cars you had 1 coil per cylinder then came the Distributor and a 1 coil set-up if the 1 coil went bad miles from home, Start walking. If 1 coil goes south in Henry's original system drive home on 3 cylinders (or replace with your spare) the single coil and distributor was with us until the late eighties when the coils moved to each cylinder so the computer could control each cylinder. Go Figure
George-Lake Ozark - How did you attach the new terminal block to the firewall? I don't see any "through-bolts". Is that a wood or metal firewall?
I need to do a "rat's nest" clean-up job to my wiring like you did George. Just not too sure how to mount the new terminal block that I ordered from Lang's to my '27 metal firewall,... anybody???
Harold , it uses two (?) screws from the back . Arms need to be long enough to do it by yourself.
Tom, I'm on the TrueFire also .Dad got it the first year it came out '03 (?) The old unit gave me a few problems. I bought a new one about two years ago and it works great, I like it a lot.
George, can the TrueFire operate on the magneto? Or is that battery only?
Tom, Batt only !!!!. Mag will burn it up.
Thanks George, good to know. So does anyone out there know where I can find a decent coil box, set of coils, and timer for a 27 T?
Most of the dealers who sell new parts also have used parts not listed in their catalogues. Others sell used and NOS parts and don't have catalogues. In both cases you have to contact them and ask.
Model T Haven, KS (620) 365-6709 email@example.com
Lang’s, MA (978) 297-1919 www.modeltford.com
Bob’s, IL (815) 633-7244 ModelT2001@comcast.net
Snyder’s, OH (330) 549-5313 firstname.lastname@example.org
Chaffin’s, CA (951) 735-4791 www.chaffinsgarage.com
Ron Paetz, Lone Pine Enterprises, WI (608) 604-7534 email@example.com
Julius & Marvin Neunhoffer, TX (830) 257-8168 firstname.lastname@example.org
Dave Huson, 2116 Charro Ave. Longmont, Co. 80504
Bob Hagelgantz, KS (785) 731-5285 email@example.com
Birdhaven Vintage Auto Supply, IA (515) 674-3949
Antique Auto Ranch 2225 N. Dollar Rd. in Spokane Valley, WA 99212
323 W MN ST
St Joseph, MN 56374
I also carry a line of new, reproduction parts & have tons of used parts even after "the big move" !
Steve's T Works, LLC
My '24 came to me without a magneto (no magnets, just oil slingers) and a Truefire. It runs just fine after I lengthened my timing rod and reset the timing per the Truefire instructions (the previous owner had set the timing with the Ford tool, so the timing was way too advanced).
My car also came to me with a 6V alternator instead of the stock generator. The alternator also works just fine.
------ Warning - personal opinion follows! ------
That said, if my car had come with a working magneto, I would take the money that was spent on a Truefire and purchased one of the new TW timers and five freshly rebuilt Ford coils from the Coilman or other well-known coil rebuilder.
I have accumulated all the parts required to convert the car back to a totally stock engine and charging system for the day that the engine has to come out for some reason. In the meantime, I plan to enjoy the car as it is.
--- End of opinion section, returning to your normal broadcast. ---
Steve, if you want to post contact info I'll add it to my list.
Mark, I was leaning towards the true fire for it's electronic reliability, however like the distributor I have now it can only run on DC. Since I need a coil box and timer anyhow for the true fire, I figured I may as well as get the coils so I have the option of running on the magneto if needed. That being said I still don't know if I have a working magneto yet, still trying to get the thing to fire up for more than a few seconds. The lady seems to be a little unwilling to wake up from it's 10 plus year nap.:>)
Steve, that picture you posted of the dusty engine on the floor, is that coil box all metal? Or is it wood painted black with a metal lid? Could you post a close up picture of the coil box alone with the lid open?
When you get the engine running long enough, here is the procedure for testing your magneto in the car - it uses an 1156 light bulb and an analogue (not digital) volt meter:
Steve's T Works, LLC
Model T Ford Service, Repair, New & Used Parts.
Mark, thanks for the magneto test procedure, will definitely be utilizing it.
Steve, thanks for the pictures of the coil box. I can now see why true fire wants your internal dimensions before filling your order. In the pictures it appears the box has a divider in the center, am I seeing that correctly? In the 3rd picture (the 2nd with the lid open) there appears to be what looks like a contact. What is the purpose of that contact? I'm also glad to see that the coil box fits with the optional water pump in place.
Sorry Steve, what I meant to say is there is what looks like a contact on the what appears to be the center divider. One other question, if I opt for the true fire ignition, is that divider removable? Thanks again.
From 1922 on, all coil boxes had the little center divider to keep the front from bulging out.
All coil boxes have a strip with four contacts in the bottom, and two rows of four in the back panel.
If your T is infested by a water pump, here's some information on that: http://dauntlessgeezer.com/DG96.html.
Steve, thanks for clearing that up for me. Also thanks for the link on the water pump.
Steve, I take it your not a big fan of water pumps on Model T's. I agree if all is well with the coolant system it should not be needed. I have yet to make up my mind on the one that came on my car, but I do have one question for you. How do your T's fair in parades with out a water pump?
Tom, I have a good old aftermarket (from back in the day) flat tube radiator on our '25 coupe. I can't make it boil in 95+ degree heat with NO waterpump, and believe me, I have tested it! JMHO Dave
I'm no help on that one. I haven't done any parades.
Here in Texas it is often 105 degrees on July 4. I have done as many as 3 parades on July 4 the same year. Model T's can run all day long in parades without overheating if you know the drill:
1. Let the engine run at fast idle all the time. Don't let the idle speed get so slow you can count the fan blades. This will keep air flowing across the radiator and keep you from fouling plugs.
2. Advance the spark lever 1/2 way. If you run with the spark fully advanced or fully retarded it will overheat.
3. Be sure you have plenty of gas. A T will run lean if the fuel quantity gets too low and you are on a slight incline. For T's with the tank under the seat, you should consider 2 gallons remaining = empty.
4. Don't rev the engine to start from a dead stop. Just slowly mash the low pedal and let the flywheel do its job. That way you won't generate a lot of engine heat and you won't generate a lot of heat in your low band.
5. Have fun!
I have run all of my T's in weather as hot as 115 degrees when I lived in Tucson. No water pumps, never overheated.