The year 1920 was extraordinary in many ways, yet we don’t seem to remember many things about it today. Ford production increased significantly from the prior year, but most automakers had results exactly the opposite of Ford. Many auto manufacturers went out of business. The depression of 1920 – 21 is hardly; if ever; mentioned today; but it was severe and profound for those who lived through the time. Much of the economic trouble was caused by the end of World War I (simply known as The Great War at that time). Returning soldiers came back to find there were no jobs available, exports to Europe fell due to strife and hardship in that part of the world. Meanwhile the Volstead Act went into effect on January 16, 1920 ushering in a shadow economy of smuggling, speakeasies, and liquor trade that was not taxed yet cost the government lots of money while trying to enforce the unpopular new law. President Wilson had been incapacitated since a major stroke October of 1919, never to recover. A flu epidemic had been sweeping the world since 1918. By December 1920 it had killed about four to five percent of the world’s population, as many as 100 million people. It was the worst epidemic in recorded human history.
Ford built about 941,000 cars and trucks in 1920 model year, easily holding first place in the industry. Model T body styles continued from the previous year, with the touring being easily the most popular body style, available either in the basic hand cranked version with magneto powered headlamps and kerosene tail and cowl lamps, or in the fancier and more expensive version with starter, battery, 6 volt headlamps and tail lamp, and demountable wheels including a spare rim (a spare tire was optional at extra cost). Prices for the Model T touring started at $575 for the basic crank started version, or $675 for the fancy Model T equipped with electrical starter. Ford continued to supply its cars with the two speed planetary transmission controlled by foot pedals. The rest of the industry sold cars with 3 or more speed manual transmissions. The Model T engine continued as before, with 20 advertised horsepower from four cylinders and 176 cubic inches.
In many cases the Model T generator brushplate lead (Null Point) has been changed by people who do not fully understand what they are doing. The usually results in a generator that is charging excessively, not charging at all or will not “build up” to starting charging on its own (a detailed description of the term “Building up” may be found at https://modeltfordfix.com/the-model-t-ford-battery-charging-system-by-ron-patterson/ ). Brushplate lead should not be used to set the generator charging rate. The brushplate lead should only be adjusted when the generator is rebuilt or repaired and would not normally be changed when doing normal maintenance by the vehicle operator. Here is a procedure that will allow you to correctly reset the brush plate lead with the generator mounted on the engine as opposed to removing the generator and setting the brushplate lead on a test bench. (This is not the procedure for setting the brushplate lead on a dynamic generator test stand) To help familiarize yourself with brushplate lead adjustment procedure Figure 1, shows the location of the four brushplate clamp ring 6-32 X 5/16 machine screws (This 5/16 length is critical to prevent the end of the screws interference with the Commutator) and Figure 2 shows a brush plate installed in a brush cap, a clamp ring and the brushplate mortise which the brushplate moves within.
By far, the most common Model T Ford starting motor failure is the internal connection between the 3/8-16 terminal bolt and internal buss bar that connects to the ends of the two adjacent field windings as shown in Figure 1. When I disassemble starter cores for rebuilding, I usually find 90% of them have this problem.
Once again we are privileged to have another fine article written by Ron Patterson.
When the Model T Car was originally developed Henry Ford insisted that it have a self-contained power source for the Ignition System so owners would not have to rely upon battery power. All inexpensive cars at that time used dry cell batteries to power Trembler coils for ignition. A dead battery would disable the vehicle until it had been replaced. Many people carried extra batteries, but commonly forgot to keep a supply of charged batteries on hand. These batteries were not rechargeable and were a common nuisance to maintain.
While Ford’s idea sounds anachronistic today, it was a major selling point of the new Model T Ford in 1908.Henry Ford’s idea was implemented by Joseph Galamb and Edward Huff in the form of the internal flywheel driven alternating current generator (the Model T Magneto); sixteen permanent magnets mounted on the flywheel rotating (rotor) near a ring of sixteen fixed field windings (stator) to produce ignition current.
In this magneto system spark timing was controlled by a combination of Magneto current pulses that occurred every 22.5 degrees of flywheel rotation and the Timer which was connected to the driver manipulated spark control lever (advance and retard) on the steering column.
For those interested in more complete details of the entire system read our article entitled “The Model T Ford Ignition and Spark Timing” and may be found at the following link:
This week we are blessed to have a very instructive article written by Ron Patterson and Bob Cascisa.
Over the years I have had the opportunity to help many with Model T electrical system problems. I discovered that many Model T Fords were incorrectly wired. In some cases those cars were being driven and the owner thought everything was working correctly. I quickly ceased believing anything anyone told about their car and developed some simple tests that will validate if the wiring is correct so one could rely on the dash Ammeter to provide reliable data when looking for problems.
I suggest you first read the article “Model T Ford Battery Charging System” to fully understand how the charging system operates. This article can be found
Here in the Model T Ford Fix website (modeltfordfix.com).
The basic function of the Model T Ford Charging System is to maintain the Battery at a proper level of charge to provide sufficient electrical power for the starting motor, ignition and headlamps while providing an Ammeter indication the system is working properly. The Ammeter indicates the net power in the electrical system. If it indicates a Charge, the generator is providing sufficient power to meet the electrical demands (Ignition and lights) and to keep the Battery charged. If it indicates a Discharge, the Generator is not providing enough power to carry the load and keep the Battery charged. A dead or weak Battery will result by driving the car with the Ammeter continually showing a discharge condition.
When working on Model T wiring it is important to be sure you are using a correct wiring schematic. Many commonly available wiring schematics are incorrect, particularly in the charge/discharge circuit wiring. Additionally, many reproduction dash Ammeters do not have their polarity clearly marked + or – on the terminals and as a result is commonly wired incorrectly. These wiring errors can allow the Ammeter to show only discharge current and no charge current or vice versa. I recommend you use the wiring schematic in Figure 1. This wiring schematic is electrically correct for the starter-generator equipped Model T.
Here is an easy way for anyone with limited electrical knowledge to functionally check the charging system and correct any trouble.