The Ford Barn

BRENT in 10-uh-C · 10-06-2022, 09:36 AM

Is there a way of checking polarity of a reproduction Model-A vs. a Model-T generator cut-out? I have several reproduction cut-outs in inventory that are not labeled and likely a couple are Model-T cut-outs, so differentiating the difference and properly labeling them would be nice.

TIA!!

katy · 10-06-2022, 09:56 AM

Methinks an original style cut-out is not polarity sensetive. I may be wrong.

ndnchf · 10-06-2022, 05:06 PM

You say reproduction cutouts. Are they mechanical points or diode type? Original points type don't care about polarity, they will work on either system. Diode type are polarity specific and can be checked with a ohmmeter. I use a variable power to test the points type.

This is a short video of me testing an original cutout using a variable power supply.

https://youtu.be/MbITShRm6W4

eagle · 10-06-2022, 05:49 PM

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Most DVOMs have a diode check. Use that. The red lead indicates the positive side of the diode to get current flow, meaning if the diode check beeps and shows .6V or so, that is the voltage drop and direction of current flow. If it shows open, reverse the leads.

10-06-2022, 09:36 AM	#1
BRENT in 10-uh-C Senior Member Join Date: May 2010 Location: Eastern Tennessee Posts: 11,520	Checking Generator Reproduction Cut-out Polarity Is there a way of checking polarity of a reproduction Model-A vs. a Model-T generator cut-out? I have several reproduction cut-outs in inventory that are not labeled and likely a couple are Model-T cut-outs, so differentiating the difference and properly labeling them would be nice. TIA!! __________________ . BRENT in 10-uh-C . www.model-a-ford.com ...(...Finally Updated!! ) . Last edited by BRENT in 10-uh-C; 10-06-2022 at 10:15 AM. Reason: added the word 'reproduction' for clarity.

10-06-2022, 09:56 AM	#2
katy Senior Member Join Date: Jun 2015 Location: Red Deer, Alberta Posts: 5,046	Re: Checking Generator Cut-out Polarity Methinks an original style cut-out is not polarity sensetive. I may be wrong. __________________ If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn!

10-06-2022, 05:06 PM	#3
ndnchf Senior Member Join Date: May 2012 Location: Fredericksburg, Virginia Posts: 765	Re: Checking Generator Reproduction Cut-out Polarity You say reproduction cutouts. Are they mechanical points or diode type? Original points type don't care about polarity, they will work on either system. Diode type are polarity specific and can be checked with a ohmmeter. I use a variable power to test the points type. This is a short video of me testing an original cutout using a variable power supply. https://youtu.be/MbITShRm6W4

10-06-2022, 05:49 PM	#4
eagle Senior Member Join Date: Aug 2011 Location: Eagle Bend, MN Posts: 2,025	Re: Checking Generator Reproduction Cut-out Polarity Sponsored Links (Register now to hide all advertisements) Most DVOMs have a diode check. Use that. The red lead indicates the positive side of the diode to get current flow, meaning if the diode check beeps and shows .6V or so, that is the voltage drop and direction of current flow. If it shows open, reverse the leads. __________________ "There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."