I have a 27 tudor my first T. Today I stated the car when I turn the car off it did not turn off when I turned it to mag it ran better. So I adjusted the carb. So as I went to turn the car off the wire to the generator was smoking. HELP

Tim,
Sounds like a couple of problems.

When you turn the key to OFF the engine should shut down, but if you turn the key from BAT to MAG and only pass through OFF it should not turn off. If you turned the key to OFF and it did not turn off you have a worn out ignition switch.

The engine should run better on MAG, that is normal. BAT is usally used to start then switch over to run on MAG. BAT position on the ignition switch sends 6VDC from the battery to the coil box, MAG sends AC power from the magneto to the coil box. You can start and run on either position, but to start on MAG you should advance the spark about 3-4 notches and of course when starting on BAT always fully retard the spark lever. This is true if using the electric starter or hand cranking.

Your comment regarding adjusting the carb seems out of place or at least not relevent to your electrical question.

A smoking gen wire is bad. but it means that too much amperage is running through the wire, or at least more than it was designed to accomodate. The generator wire on older reproduction harnesses are under size, maybe 16 gage, the newer ones seem to be 12-14 gage, although the only problem with the smaller gage gen wires is usally less current to charge the battery, not that it smokes. Now if your generator is running wild it can burn your wire. You did not give any ammeter readings, with the engine not running it should read 0, with the engine not running and the lights on it should show a discharge of 8-14 amps, and with the lights off and the engine running it may show 0-12 amps depending on how the generator is adjusted. You will smoke the gen and gen wire if you run the engine with the battery cable disconnected. I suspect you have a bad generator. Ron the coil man rebuilds them, In any event I would suggest you not run the angine again until you fix the problem or you risk an electrical fire.

Disconnect the battery NOW!

Sounds like the cutout may be stuck and/or the generator is adjusted too high. (Output) When you say it wouldn't shut-off, do you mean the engine was dieseling? This can be caused by carbon in the heads/valves/plugs or by overheating. It's quite normal for the engine to run better on Mag than battery. Consider yourself fortunate to have a well operating Mag.

The generator wire smoking sounds like the cutoff was stuck. If this wire is not immediately removed, you could burn up the generator or start another fire in the wiring. My dad once had a Model A on which the generator wire got hot and it caught the oil on the outside of the engine on fire!

Need to replace the cutout and/or the generator. Don't replace the generator unless it won't charge after you replace the cutout.

The ignition problem is most likely a bad switch or the wires behind the switch are not hooked up correctly. You need to use a wiring diagram to be sure the wires are right. It is in the black Model T manual, or the book Electrical system printed by the club. There are also diagrams on the forum on other posts.
Norm

Ken,
Unless I misunderstood Tim's statement, the gen wire was smoking prior to shutting down the engine, in that condition, the cut-out should be closed so that is normal and should not cause the gen wire to smoke. Of course if it smoked after it was shut down I agree that it my indicate a cut-out stuck closed. Disconnecting the battery is also good advice. Adding a 25-30 amp in-line fuse for the small battery wire at the starter switch is also good insurance.

Thanks for responding. On batt while running the amp meter shows a discharge. On mag it shows zero. Adjusting the carb was to give a time line. I drove the car last year about a block with no problem. thanks again

Tim,
I suspect the RPM's were low while running on BAT and higher while running on MAG, running on GEN or MAG will have no effect on the ammeter reading, but RPM will.

Did your gen wire smoke while the engine was running?

Was your battery connected the entire time the enigne was running?

Have you disconnected the batery now like Ken suggested?

Gen wire was smoking with engine running. Battery was connected and I have disconnected. I think you are right about the sticking cutout. This has ben sitting since the late 1930s. But the starer work fine so I thouth or hoped the gen would too.

Tim,
The cut out is nothing more than an electromagnetic switch that will open or close the circuit between the generator and battery. When the engine is running the generator will produce power which will close the cutout thereby conneciting it to the the battery via the gen wire through the ammeter to the ignition switch to the wire that runs to the hot side of the starter switch. now when cutouts get old the points start to stick and will keep the circuit closed even when the engine is not running and the generator is not producing electricity, this condition will alow the batery to send current to the generator which at very least will cause your battery to discharge and at worst it may cause a fire. Replacing the cutout will solve that problem untill the points start to stick again and the problem comes back. The other shortcomming with the cutout is that it will always charge your battery at a rate determined by the adjustment of the 3rd brush. For short trips a higher charge rate is set, and for long tours a lower charge rate is set, but it is alwauys charging the battery if it needs it or not. This over chargining will cause the batttery to boil and evaporate the electrolite which will eventually lead to a dead battery. This is not a dangerous situation, but it is a nusiance and shortens battery life. John Reagan has a Fun Projects voltage regulator, I have one, it will vary generator output, so when you start up the T after several weeks and the battery may be a little low, the charge rate is high, as the battery charge is restored the voltage output is reduced and best of all, when the battery is fully charged, the VR stops charging it.

Now a smoking gen wire while the engine is running is not an indication of a stuck cutout since the cutout should be closed (completing the circuit) while the engine is running, it therefore indicates a runaway generator which is producing way too many amps. My advice is to talk to Ron Patterson regarding a rebuilt generator and John Reagan regarding a Voltage regulator. But a new voltage regulator will not correct a sick generator, do both.

Jeff Thanks for your help I will look into a gen rebuilt gen and this voltage regulator

The ammeter should not show a discharge while the engine is running unless you have the lights on. It should read the same while running on battery or on mag. If you have the battery connected backward the ammeter would show a discharge while the engine was running and it would show a charge when the lights are on even if the engine were not running. Sounds to me as though you have a problem with the wiring. The ignition switch should have no affect with whether the battery is charging or discharging, however, if it were wired in such a way that it would open the circuit between the generator and the battey when the switch was turned off or to mag, it would cause the generator to get too hot because it would have no battery to charge. There are 3 connections to the ignition switch. One goes to the coils, one goes to the battery and the other goes to the magneto. It's possible that the generator is connected to the magneto when you are turned to batt and that is why it is not running very well. When you switch to magneto, the generator is not connected to anything. If this is the condition, it is not good for the magneto either.
Norm
Norm

DO NOT RUN THE ENGINE WITH GENERATOR DISCONNECTED unless the generator output is grounded, or you have a voltage regultor fitted. (Don't ground the generator output if a voltage regulator is fitted.) Otherwise you will burn out the generator. Without a load on the generator the voltage will keep climbing until the field coils burn out.

What hasn't been mentioned here is insulation breakdown to the frame of the cutout. That is more likely to be the source of excessively high current. The resistance of the generator windings would not be low enough to allow that sort of current to flow if it was just stuck cut out contacts. The other thing that will do it which has happened to me, is the screw on the battery terminal of the cutout touching the generator body. As I had a 30A fuse, the wire was saved from going up in smoke.
I used blank fibreglass printed circuit board to replace the insulation material, and soldered all the connections, rather than relying on unreliable rivets, when I rebuilt mine.

Just a couple points of clarification.
The wire from the generator cutout to the ammeter and from the ammeter to the starter switch should be a #12 wire.
Some wiring harness's have used a #14 and this can cause problems under certain conditions.
If you want a fuse use ONE and install it like the simple FunProjects TFK-1 kit. You do not need anything else.
Ron the Coilman

Since we're talking about a 27 Tudor I want to add one more little thing.
I tore my hair out over a charging problem.
My car is 12V with an alternator, but the problem would be the same with a 6V generator car.
Check the connections at the terminal strip on the firewall.
Sometimes I'd have 12V at the alternator, sometimes I'd have 6V or 3V or nothing?
It finally turned out that the connection on the terminal strip had pulled out and the slightly loose wires had burnt between the terminal ends from trying to conduct voltage.
Since the terminal strip is shot, I cleaned up the terminal ends and fastened them together with a small screw and nut for now. No more wierd charging problems.
Moral to the story. Don't start swapping out electrical parts until you are SURE you have a complete, solid, circut between them.

The wiring and terminal strip are new. Norman Kling emailed me about a wiring diagram in a earlyer Forum. By looking at it I have seen that I have my gen wire going to my amp meter first and then to the switch. According to this diagram it goes to the switch frist and then to the meter. Could this be the problem.

Tim
I doubt that is your problem. It is common to see the wire from the generator connected to either the switch or the ammeter. Either way it is electrically the same. This of course assumes the jumper between the switch and ammeter and the wire to the battery is correctly wired.
Ron the Coilman

Re-reading the above, I think you have a problem with one coil. I think when you turn it to Batt, you are grounding the wire coming from the generator. That would explain the ammeter going to discharge and the hot wire from the generator. However, the coils would not buzz with a dead short to ground unless only one coil was grounded. I think one coil has an internal ground or short to ground, possibly only grounding when the timer is contacting for that coil. It could be that when you looked at the ammeter, you saw the discharge because contact was made for the bad coil. Then when you switched to mag, the battery was not connected to ground. This is just a theory, but worth checking out.
Norm