ignition coils

[meadowbrook]

My Dodge still has 6v pos gnd, no resistors needed

[meadowbrook]

Speaking of ignition, just had the pleasure of filing the VW's points flat and tuning the engine for the season.

Was kind of therapeutic.

Will do the Dodge next, if needed.

I know Bosch point are hard tungsten and thus are filable.

Are the Mopar ones throwaway or also filable, if needed?

[ACJCF2]

I did some reading on the coil subject in previous posts and I performed the ohm resistance test (my coil has a 1.5 ohm) value. The shop manual does not give this spec for the 6 volt coil. Does anyone have this value? Frankly I do not know what coil is on the car. 12v or 6v. So I needing a baseline.

Secondly, my 4 post ceramic resistor is beyond help. I am assuming (I know...) that the resistance of the new ballast should equal the coil resistance. Is this correct?

Thanks,

Jim

[Plymouthy Adams]

you need to read a bit more on the subject...4 post block ceramic is dual resistor and for certain electronic application...

Edited May 9, 2015 by Plymouthy Adams

[ACJCF2]

I am wanting to replace it with a two post resistor hence my post.

[janan5243]

If the long forgotten facts are falling out of the cobwebs correctly, I believe a four terminal resistor was used on early Mopar electronic ignition. Power is routed thru one resistor with a higher voltage for starting & then thru the other with a lower voltage for running. I just spoke to someone that said Willys also used them.

[Don Coatney]

My resistor carries one circuit only. But I use a 4 pole solenoid using one pole for full 12 volt power to the coil by-passing the resistor when the starter button is energized.

[ACJCF2]

Don, I inherited this 49 Coronet previously converted to 12 volts. Circa 198X. It has a AC Delco GM three wire alternator and the mechanic installed a dbl coil resistor. The coil ohms out at 1.5 ohms. The broken part of the resistor ohmed at 1.7 ohms (side the coil was connected to) and the unused side reads 5.2 ohms.

Further, I am not sure if the coil is a 6 volt coil or if a 12 v coil was installed during conversion.

I tried to be clear and succinct when I ask a question. All I want to know is, should the ballast(coil) resistor ohm reading match that of the coil? The shop gives no baseline. I've read till I'm blind. I don't mind researching, I love it, but golly, I got straighter answers on the 54 Ford Club forum.

I may just spring for a new coil and resistor for 1957 model Dodge 230 I-6.

This Mopar stuff is a new skill set for me. Be patient.

Jim

[ACJCF2]

Don, I would like to learn more about wiring this type solenoid.

[Dave72dt]

I did some research on the subject. You're correct, if the source I found is correct. The idea is to drop the voltage of a 12v coil to 6v at the points. Measure the primary resistance of the coil you have and match to that.

[Dave72dt]

4 post solenoids, typically found on Fords, 2 heavy posts and a starter activation post marked S. The fourth post, marked I goes directly to the coil. It only has power to the I terminal when the starter solenoid is activated.

[ACJCF2]

Thanks Dave for confirming my coil resistor question and for helping me understand the four post solenoid wiring.

Jim

[Don Coatney]

I thought my original answer was straight forward but I guess you did not understand what I was saying.

 

 

Pictured is the coil and resistor I use. This coil is not internally resisted. It is possible to buy a coil that is internally resisted and when doing so no external resistor is required. However when using an internally resisted coil it is not possible to by-pass the resistor for a full 12 volt startup.

 

 

Pictured below is the Ford 4 post solenoid I have installed on my car. Dave described the operation of this solenoid. Post #3 is hot only when the solenoid is energized and I have it wired directly to the ignition coil bypassing the resistor giving a full 12 volt charge for startup. One word of warning when using this setup. If you use a remote starter button connected to the solenoid under the hood the engine will fire every time the solenoid is energized even with the ignition switch in the off position.

 

 

[ACJCF2]

Thanks much Don.