The Ford Barn

1931fordmodela · 09-02-2017, 03:47 PM

When I switch the ignition switch to magneto the car stops running, can any one tell me what I should be looking for to diagnose the problem? I am driving a 1926 Ford Model T coupe. I bought the car this way. It runs great and is in awesome condition, so I would like to make sure everything works in the car.

J Franklin · 09-02-2017, 04:14 PM

First test at the mag post on the hogs head for AC voltage while running. It should increase with higher RPM. If it has running voltage next check the batt/mag switch and wiring for any open or bad connections. Report your findings here.

redmodelt · 09-02-2017, 05:39 PM

You need to use an analog meter, standard digital type will not work because of interference from the mag using . Start also by checking connections.

29spcoupe · 09-02-2017, 06:29 PM

If very low or no voltage out of mag plug, remove the mag plug and check for lint on the end of the plug. They sometimes collect lint from the band material. If no lint and no voltage, your magnets are probably bad. They can be recharged. John

FRANK PKNY · 11-30-2017, 02:03 PM

John Are you the Model T guy from Rhinebeck NY LOL I know you well old buddy! You have model T bands in your blood.

29spcoupe · 11-30-2017, 06:08 PM

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Hi Frank, had to go for a blood test the other day. The doctor pulled Kevlar into the syringe.

Low Compression · 11-30-2017, 09:23 PM

While doing this testing, make darn sure that you don't accidentally allow DC voltage to enter the mag post. If your magneto is alive now- it won't be after the accidental DC voltage makes contact. The magnets will be de-magnetized.

Just a friendly warning. I wish someone had warned me!

J Franklin · 11-30-2017, 09:46 PM

As the magnets can be discharged in the car so can they be charged, it in the book. you can use any volt/ohm meter while the car is not running.

pgb24t · 02-09-2018, 05:11 PM

What would cause a magneto to suddenly die? I recharged my own magnets, shimmed and installed, and was running great. One day the car died on the mag side while driving. I checked the mag post and no lint. No noise in the transmission running on battery. What happened? Thanks

pj's junkers · 02-09-2018, 05:20 PM

They read "Silas Marner" while you were driving

29spcoupe · 02-09-2018, 06:51 PM

I would check the ignition switch to see if there is a loose wire. How long ago did you recharge the magnets. They can loose strength. What is your method for recharging? You should follow the directions in the Dyke's manual to be sure they are charged completely. I think, if I remember right, you need 36 volts to charge the magnets in the car. You also need a compass to be sure to get the correct north and south poles to line up. John

09-02-2017, 03:47 PM	#1
1931fordmodela Junior Member Join Date: Nov 2013 Location: Pitman NJ Posts: 8	Magneto Question When I switch the ignition switch to magneto the car stops running, can any one tell me what I should be looking for to diagnose the problem? I am driving a 1926 Ford Model T coupe. I bought the car this way. It runs great and is in awesome condition, so I would like to make sure everything works in the car. __________________ Mark Papa

09-02-2017, 04:14 PM	#2
J Franklin Senior Member Join Date: May 2010 Location: Oregon Posts: 5,962	Re: Magneto Question First test at the mag post on the hogs head for AC voltage while running. It should increase with higher RPM. If it has running voltage next check the batt/mag switch and wiring for any open or bad connections. Report your findings here.

09-02-2017, 05:39 PM	#3
redmodelt Senior Member Join Date: May 2010 Location: Portland OR Posts: 6,340	Re: Magneto Question You need to use an analog meter, standard digital type will not work because of interference from the mag using . Start also by checking connections. __________________ I know the voices aren't real but damn they have some good ideas! Last edited by redmodelt; 09-02-2017 at 07:52 PM.

09-02-2017, 06:29 PM	#4
29spcoupe Senior Member Join Date: Aug 2014 Location: Rhinebeck, NY Posts: 761	Re: Magneto Question If very low or no voltage out of mag plug, remove the mag plug and check for lint on the end of the plug. They sometimes collect lint from the band material. If no lint and no voltage, your magnets are probably bad. They can be recharged. John

11-30-2017, 02:03 PM	#5
FRANK PKNY Senior Member Join Date: May 2010 Location: POUGHKEEPSIE NY 12601 Posts: 1,016	Re: Magneto Question John Are you the Model T guy from Rhinebeck NY LOL I know you well old buddy! You have model T bands in your blood. __________________ [email protected]

11-30-2017, 06:08 PM	#6
29spcoupe Senior Member Join Date: Aug 2014 Location: Rhinebeck, NY Posts: 761	Re: Magneto Question Sponsored Links (Register now to hide all advertisements) Hi Frank, had to go for a blood test the other day. The doctor pulled Kevlar into the syringe.

11-30-2017, 09:23 PM	#7
Low Compression Junior Member Join Date: Jul 2013 Posts: 3	Re: Magneto Question While doing this testing, make darn sure that you don't accidentally allow DC voltage to enter the mag post. If your magneto is alive now- it won't be after the accidental DC voltage makes contact. The magnets will be de-magnetized. Just a friendly warning. I wish someone had warned me!

11-30-2017, 09:46 PM	#8
J Franklin Senior Member Join Date: May 2010 Location: Oregon Posts: 5,962	Re: Magneto Question As the magnets can be discharged in the car so can they be charged, it in the book. you can use any volt/ohm meter while the car is not running.

02-09-2018, 05:11 PM	#9
pgb24t Junior Member Join Date: Jan 2015 Posts: 4	Re: Magneto Question What would cause a magneto to suddenly die? I recharged my own magnets, shimmed and installed, and was running great. One day the car died on the mag side while driving. I checked the mag post and no lint. No noise in the transmission running on battery. What happened? Thanks

02-09-2018, 05:20 PM	#10
pj's junkers Senior Member Join Date: Aug 2010 Location: Vivian, La Posts: 215	Re: Magneto Question They read "Silas Marner" while you were driving

02-09-2018, 06:51 PM	#11
29spcoupe Senior Member Join Date: Aug 2014 Location: Rhinebeck, NY Posts: 761	Re: Magneto Question I would check the ignition switch to see if there is a loose wire. How long ago did you recharge the magnets. They can loose strength. What is your method for recharging? You should follow the directions in the Dyke's manual to be sure they are charged completely. I think, if I remember right, you need 36 volts to charge the magnets in the car. You also need a compass to be sure to get the correct north and south poles to line up. John