The Ford Barn

CP · 07-26-2016, 07:11 PM

Hello all once again,

just realized there is an original resistor under the dash that I never knew was there.

From other posts....i found this "14.2V / 3.5 Ohms = 4 Amps"

I'm running 12volts 1948 flathead with a Mallory electronic distributor.

Mallory paperwork requires ballast resistor. I'm running a 12 volt coil. and I have a ceramic resistor between the battery and the "+" of the coil. Plus the resistor I did not know was there. Lately, when the engine gets "hot"....it is difficult to start.

wondering 2-questions...

1. what is the "stock" resistor in ohms (original 6v system) 1935
2. from what ive read, 4 amps is what we want for any engine (6v or 12v).

I know the resistance changes with "heat"...so I'm thinking the ceramic coil I have is "too much" yet i do not know how to test hot or cold.

any thoughts? I am not knowledgeable in this...

I'm thinking I want to keep the original resistor as is...say it is 1.5 ohms...I will then purchase a 2.0 ohm ceramic resistor and be "all set" no?

I saw another post that napa has many ceramic resistors available and i think 1.8 ohms was the most i could get..

If that is the case...is it better to have more resistance or less? I'm confused.

CP

paul2748 · 07-26-2016, 07:37 PM

Are you running a 12 volt, negative ground system?

CP · 07-26-2016, 07:46 PM

yes

BUBBAS IGNITION · 07-26-2016, 07:55 PM

Original resistor is .6 ohms.... Leave it as is and use a 1.5 ohm coil. Should be fine. Total 2.1 would be approx six amps, Mallory cuts out at 8 amps with current limiting .
Napa. IC 12 SB is ac1.5 ohm coil

CP · 07-26-2016, 08:02 PM

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thank you BuBBA..

07-26-2016, 07:11 PM	#1
CP Senior Member Join Date: May 2010 Location: Cape Cod Posts: 159	resistor for 12v with original 1935 inline Hello all once again, just realized there is an original resistor under the dash that I never knew was there. From other posts....i found this "14.2V / 3.5 Ohms = 4 Amps" I'm running 12volts 1948 flathead with a Mallory electronic distributor. Mallory paperwork requires ballast resistor. I'm running a 12 volt coil. and I have a ceramic resistor between the battery and the "+" of the coil. Plus the resistor I did not know was there. Lately, when the engine gets "hot"....it is difficult to start. wondering 2-questions... 1. what is the "stock" resistor in ohms (original 6v system) 1935 2. from what ive read, 4 amps is what we want for any engine (6v or 12v). I know the resistance changes with "heat"...so I'm thinking the ceramic coil I have is "too much" yet i do not know how to test hot or cold. any thoughts? I am not knowledgeable in this... I'm thinking I want to keep the original resistor as is...say it is 1.5 ohms...I will then purchase a 2.0 ohm ceramic resistor and be "all set" no? I saw another post that napa has many ceramic resistors available and i think 1.8 ohms was the most i could get.. If that is the case...is it better to have more resistance or less? I'm confused. CP

07-26-2016, 07:37 PM	#2
paul2748 Senior Member Join Date: May 2010 Location: Midland Park, NJ Posts: 4,406	Re: resistor for 12v with original 1935 inline Are you running a 12 volt, negative ground system? __________________ 48 Ford Conv 56 Tbird 54 Ford Victoria

07-26-2016, 07:46 PM	#3
CP Senior Member Join Date: May 2010 Location: Cape Cod Posts: 159	Re: resistor for 12v with original 1935 inline yes

07-26-2016, 07:55 PM	#4
BUBBAS IGNITION Senior Member Join Date: May 2010 Location: SPEEDWAY INDIANA Posts: 4,148	Re: resistor for 12v with original 1935 inline Original resistor is .6 ohms.... Leave it as is and use a 1.5 ohm coil. Should be fine. Total 2.1 would be approx six amps, Mallory cuts out at 8 amps with current limiting . Napa. IC 12 SB is ac1.5 ohm coil __________________ If it Makes Spark, we do it !!!! www.bubbasignition.com [email protected] Last edited by BUBBAS IGNITION; 07-26-2016 at 08:01 PM.

07-26-2016, 08:02 PM	#5
CP Senior Member Join Date: May 2010 Location: Cape Cod Posts: 159	Re: resistor for 12v with original 1935 inline Sponsored Links (Register now to hide all advertisements) thank you BuBBA..