The Ford Barn

36tbird · 05-13-2013, 06:47 AM

I acquired this 59A with a Mallory Magnetic Breakerless Distributor. I have put it on an engine that is mounted in my newly built test stand. I tried my new contraption yesterday and did not see any spark. That prompted me to search for a test procedure to see if the ignition module is shot. I found one set of instructions where you hook up a low voltage light across the negative pole of the coil and ground then use a screw driver to tap the magnetic pickup. If all is well, the light should flicker. I could not get a flicker.

Another test for the set up that has a remote pickup is to test the resistance across the magnetic coil to see if you get between 50 and 200 ohms. I put my trusty multi-meter leads on the soldered connections for the pickup and got about 185 ohms.

So, I'm down to thinking the magnetic pickup seems OK, but the little module that interprets and sends the trigger message to the coil must be toast. Anyone know of a test or measurement for these things that I can run on the red, green and brown wires that come out of the module? Thanks in advance.

BUBBAS IGNITION · 05-13-2013, 08:27 AM

Try this , if module is bad , Use Summitt for a new one etc,

http://prestoliteperformance.com/med...edure_0009.pdf

36tbird · 05-13-2013, 11:10 AM

Yo Bubba, thanks. Those are the instructions I followed and could get no light flicker so I reckon the thing is dead. But, checking the soldered posts where the little magnetic pickup coil is attached, I got the 185 ohm reading which is in the range mentioned in that last paragraph,

"On distributors with the pickup separate from themodule assembly, you can check the pickup using
your Ohm meter. Connect the leads from your
Ohm meter to the 2 leads of the pickup. If you
show a resistance of 50 to 200 Ohms, the pickup is
functioning correctly. If the Ohm meter shows an
open circuit, the pickup should be replaced. Once
replaced, perform the module and pickup assembly
test procedure again as shown above"

I was just wondering if there was another test or value I could measure on the leads from the module to really make sure the thing is toast as another backup to make sure I haven't screwed something up on the new, home-made engine test stand.

rotorwrench · 05-13-2013, 11:45 AM

Hall effect magnetic pick up assemblies are pretty reliable. I've only had one go bad on a Chadwick Strobex trigger set up that I use to track main rotor blades in my whole career. I think it went bad after it got smacked real hard or one of my mechanics dropped it from the top of the helicopter to the concrete pad below. A lot of the aftermarket ignition boxes are less reliable than the average chebby HEI.

BillM · 05-13-2013, 02:04 PM

In the link provided by Bubba the pickup looks like the typical Ford or Mopar pickup so I believe you could test it by rotating the dist shaft and using your voltmeter to look for AC voltage out of the pickup. An analog meter would be best. See my web page for more info. I would think you could drive a HEI module with the Mallory pickup.
http://myplace.frontier.com/~wgmumaw...rsionBills.htm

BUBBAS IGNITION · 05-13-2013, 02:22 PM

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Quote:

Originally Posted by BillM

In the link provided by Bubba the pickup looks like the typical Ford or Mopar pickup so I believe you could test it by rotating the dist shaft and using your voltmeter to look for AC voltage out of the pickup. An analog meter would be best. See my web page for more info. I would think you could drive a HEI module with the Mallory pickup.
http://myplace.frontier.com/~wgmumaw...rsionBills.htm

Actually Bill you are correct once upon a time thats what we used in some of our odd conversions. The little magnetic pulse pick up generates a a/c signal to trigger the HEI or other modules as well. Smallest pickup out there !!!

36tbird · 05-14-2013, 07:39 AM

Thanks for the inputs. Given that I just put together my test stand and this is its first use, I was trying to make sure that I had not messed up some wiring that was preventing the distributor from working. I'm going to check that I got a good ground for the distributor and if that check's OK, then I guess I'll just have to get a new module.

05-13-2013, 06:47 AM	#1
36tbird Senior Member Join Date: May 2010 Location: nw SanAntonio, TX Posts: 940	Mallory Magnetic Breakerless Dizzy I acquired this 59A with a Mallory Magnetic Breakerless Distributor. I have put it on an engine that is mounted in my newly built test stand. I tried my new contraption yesterday and did not see any spark. That prompted me to search for a test procedure to see if the ignition module is shot. I found one set of instructions where you hook up a low voltage light across the negative pole of the coil and ground then use a screw driver to tap the magnetic pickup. If all is well, the light should flicker. I could not get a flicker. Another test for the set up that has a remote pickup is to test the resistance across the magnetic coil to see if you get between 50 and 200 ohms. I put my trusty multi-meter leads on the soldered connections for the pickup and got about 185 ohms. So, I'm down to thinking the magnetic pickup seems OK, but the little module that interprets and sends the trigger message to the coil must be toast. Anyone know of a test or measurement for these things that I can run on the red, green and brown wires that come out of the module? Thanks in advance.

05-13-2013, 08:27 AM	#2
BUBBAS IGNITION Senior Member Join Date: May 2010 Location: SPEEDWAY INDIANA Posts: 4,148	Re: Mallory Magnetic Breakerless Dizzy Try this , if module is bad , Use Summitt for a new one etc, http://prestoliteperformance.com/med...edure_0009.pdf __________________ If it Makes Spark, we do it !!!! www.bubbasignition.com [email protected]

05-13-2013, 11:10 AM	#3
36tbird Senior Member Join Date: May 2010 Location: nw SanAntonio, TX Posts: 940	Re: Mallory Magnetic Breakerless Dizzy Yo Bubba, thanks. Those are the instructions I followed and could get no light flicker so I reckon the thing is dead. But, checking the soldered posts where the little magnetic pickup coil is attached, I got the 185 ohm reading which is in the range mentioned in that last paragraph, "On distributors with the pickup separate from themodule assembly, you can check the pickup using your Ohm meter. Connect the leads from your Ohm meter to the 2 leads of the pickup. If you show a resistance of 50 to 200 Ohms, the pickup is functioning correctly. If the Ohm meter shows an open circuit, the pickup should be replaced. Once replaced, perform the module and pickup assembly test procedure again as shown above" I was just wondering if there was another test or value I could measure on the leads from the module to really make sure the thing is toast as another backup to make sure I haven't screwed something up on the new, home-made engine test stand.

05-13-2013, 11:45 AM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 18,006	Re: Mallory Magnetic Breakerless Dizzy Hall effect magnetic pick up assemblies are pretty reliable. I've only had one go bad on a Chadwick Strobex trigger set up that I use to track main rotor blades in my whole career. I think it went bad after it got smacked real hard or one of my mechanics dropped it from the top of the helicopter to the concrete pad below. A lot of the aftermarket ignition boxes are less reliable than the average chebby HEI.

05-13-2013, 02:04 PM	#5
BillM Senior Member Join Date: May 2010 Location: Everett, WA Posts: 504	Re: Mallory Magnetic Breakerless Dizzy In the link provided by Bubba the pickup looks like the typical Ford or Mopar pickup so I believe you could test it by rotating the dist shaft and using your voltmeter to look for AC voltage out of the pickup. An analog meter would be best. See my web page for more info. I would think you could drive a HEI module with the Mallory pickup. http://myplace.frontier.com/~wgmumaw...rsionBills.htm

05-14-2013, 07:39 AM	#7
36tbird Senior Member Join Date: May 2010 Location: nw SanAntonio, TX Posts: 940	Re: Mallory Magnetic Breakerless Dizzy Thanks for the inputs. Given that I just put together my test stand and this is its first use, I was trying to make sure that I had not messed up some wiring that was preventing the distributor from working. I'm going to check that I got a good ground for the distributor and if that check's OK, then I guess I'll just have to get a new module.