Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 05-17-2020, 07:04 PM   #1
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Checking an Ignition Ballast Resistor

I did a search and didn't really fine what I was looking for.

My question is, what should the Ohm reading be on a good ballast resistor and what would it be on a faulty one. Rheostat looking resistor under the dash, '36 Ford with a '46 59AB flathead.

One last question. Where do you buy a GOOD dist. condenser for a crab style distributor also a '46 59AB engine.

Thanks much.
Jeff/Illinois is offline   Reply With Quote
Old 05-17-2020, 07:29 PM   #2
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Checking an Ignition Ballast Resistor

Need some missing information here.

Original style coil or newer "can" style?

6 volt or 12 volt system?

What does the under the dash ballast resistor look like?

An original would look something like this:
JSeery is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 05-17-2020, 08:16 PM   #3
meric42
Senior Member
 
meric42's Avatar
 
Join Date: Aug 2010
Location: Blenheim, New Zealand
Posts: 869
Default Re: Checking an Ignition Ballast Resistor

The best 'off the shelf' condenser Napa FA54, doesn't look the same as original but reliable.

https://www.fordbarn.com/forum/showt...highlight=FA54
__________________
I need an 01A 1453 Brkt Spare wheel hold down for my sedan delivery - PLEASE HELP

Gotta love my '42 Sedan Delivery's - Now that I own the only two in New Zealand

http://www.fordbarn.com/forum/album.php?albumid=580

Last edited by meric42; 05-17-2020 at 08:21 PM.
meric42 is offline   Reply With Quote
Old 05-17-2020, 08:37 PM   #4
koates
Senior Member
 
Join Date: May 2010
Location: Melbourne Australia.
Posts: 2,076
Default Re: Checking an Ignition Ballast Resistor

Resistor is .5 ohms, that's half an ohm approx. A bad resistor would be a higher reading or no reading at all. Only use an original FORD made resistor as modern reproductions have been known to have issues. Regards, Kevin.
koates is offline   Reply With Quote
Old 05-18-2020, 12:40 PM   #5
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Thanks for the help here.

I forgot to mention, 6V original system with a 'modern' can type coil. The coil is maybe 5 years old it is a Standard brand part.

The under the dash resistor looks like the one pictured with a 20 amp Buss fuze attached beside it.

I will try to get out to the garage in a couple of days and let you know what I find. I will re-check that resistor it LOOKS OK not burnt or anything like that but I'll hit it with my tester

Thanks again
Jeff
Jeff/Illinois is offline   Reply With Quote
Old 05-18-2020, 12:44 PM   #6
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Sponsored Links (Register now to hide all advertisements)
Quote:
Originally Posted by meric42 View Post
The best 'off the shelf' condenser Napa FA54, doesn't look the same as original but reliable.

https://www.fordbarn.com/forum/showt...highlight=FA54
Thanks for this info, my condenser looks a lot like this one but I noticed that the wire lead is frayed and the insulation looks like it is toast. Never noticed that until I started running down the electrical gremlin.

I have plenty of fuel, fuel pump working fine accelerator pump squirts to beat the band. No spark at the plugs so I'm going that direction.

I'll let you fellows know what I find. Thanks again.

P.S. I was a Ford Parts Manager at the local Ford dealer back in the early 70's, and not a mechanic! I know the parts and what they do so that helps!

Jim Linder at Bubba's Ignition rebuilt my dissie about 7-8 years ago and did a fantastic job. I see he uses the NAPA FA54 condensor so I will call down to our local NAPA store and get one ordered
Jeff/Illinois is offline   Reply With Quote
Old 05-18-2020, 01:18 PM   #7
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,371
Default Re: Checking an Ignition Ballast Resistor

A can type coil indicates a conversion from coil on helmet remounted to can somewhere else. The can type coil conversion adapters for the helmet distributor can be problematic. If you are useing a can type (modern) coil with a 1.5 ohm primary winding and running the car on 6-volts, you won't need a ballast resistor.

If you deside to find a good core coil to fit your 1936 Helmet distributor, you can get Skip Haney to rebuild it for you. It will work better than new but you would need the original type ballast resistor with it.

http://www.fordcollector.com/coils.htm
rotorwrench is offline   Reply With Quote
Old 05-18-2020, 01:40 PM   #8
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Checking an Ignition Ballast Resistor

The ballast resistor needs to be by-passed with the modern coil. This is easy to do by moving the wire from the ignition switch to the resistor. At the resistor end remove the wire and reconnect it to the side of the resistor that has the wire going to the coil. All done. Also, be sure the ignition wire to the coil connects to the (-) terminal on the coil and the (+) terminal connects to the distributor/capacitor/points. On some coils the (-) terminal might be labeled Dist and the (+) terminal might be labeled Bat.
JSeery is offline   Reply With Quote
Old 05-18-2020, 04:14 PM   #9
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by JSeery View Post
The ballast resistor needs to be by-passed with the modern coil. This is easy to do by moving the wire from the ignition switch to the resistor. At the resistor end remove the wire and reconnect it to the side of the resistor that has the wire going to the coil. All done. Also, be sure the ignition wire to the coil connects to the (-) terminal on the coil and the (+) terminal connects to the distributor/capacitor/points. On some coils the (-) terminal might be labeled Dist and the (+) terminal might be labeled Bat.
Got it thanks did not know this.

I'm a 'Model A ' guy by trade flatheads are 'new' territory for me I can trouble shoot a Model A Ford easier than these dogs.
Jeff/Illinois is offline   Reply With Quote
Old 05-18-2020, 04:35 PM   #10
flatjack9
Senior Member
 
flatjack9's Avatar
 
Join Date: May 2010
Location: Oshkosh, Wi
Posts: 4,516
Default Re: Checking an Ignition Ballast Resistor

You need to check the primary resistance of the coil to know whether you need a resistor or not. You want a total of 1.5 ohms.
flatjack9 is offline   Reply With Quote
Old 05-18-2020, 04:55 PM   #11
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by flatjack9 View Post
You need to check the primary resistance of the coil to know whether you need a resistor or not. You want a total of 1.5 ohms.
True, but was assuming it was a standard 1.5 ohm 6v coil. As flatjack posted, it is always best to check.
JSeery is offline   Reply With Quote
Old 05-18-2020, 08:42 PM   #12
koates
Senior Member
 
Join Date: May 2010
Location: Melbourne Australia.
Posts: 2,076
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by koates View Post
Resistor is .5 ohms, that's half an ohm approx. A bad resistor would be a higher reading or no reading at all. Only use an original FORD made resistor as modern reproductions have been known to have issues. Regards, Kevin.
My answer related to the original 1936 Ford flathead ignition system. You did not state that your coil was a canister type, which may or may not require a resistor in circuit. Regards, Kevin.
koates is offline   Reply With Quote
Old 05-19-2020, 10:47 AM   #13
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by koates View Post
My answer related to the original 1936 Ford flathead ignition system. You did not state that your coil was a canister type, which may or may not require a resistor in circuit. Regards, Kevin.
Hi Kevin. It is a later 'can' type or 'cylinder' coil not the helmet coil as original. The motor is out of a '46 Ford and has the crab style distributor cap.

I ordered up a NAPA FA54 condenser I need a new one anyway mine has a bad wire lead somebody wrapped it in electrical tape it looks frayed and worn, they will have it in Wednesday.
Jeff/Illinois is offline   Reply With Quote
Old 05-19-2020, 11:18 AM   #14
38bill
Senior Member
 
38bill's Avatar
 
Join Date: Apr 2014
Location: Minnesota
Posts: 1,162
Default Re: Checking an Ignition Ballast Resistor

Also check the coil. Many aftermarket "can" type coils state right on the can if it requires a resister or not.
38bill is offline   Reply With Quote
Old 05-21-2020, 09:35 PM   #15
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Update on my 'no-fire- on the 59AB Flathead. 6V Pos. ground as original.

Coil has a resistor built in, 6V checks at 1.5 Ohms on the primary side. There is also an external resistor under the dash as original. Tried another coil also 1.5 Ohms no difference in starting. ( It has been wired this way for the last 2500 miles I have driven the truck!)

Changed condensor with a good one. No difference.

I am getting 6.1 V at the ignition switch, 6.1 V on both sides of switch w/ key on.

6.1V at the resistor on both ends. Power shows at the coil, and at the condensor w/ key on.

Voltage drops to 4.2 V across the coil and holds at 4.2V to the condensor.

I have to run errands Friday, will get back to the truck as soon as I can. I guess at this point it's either a bad coil wire or the points are closed up or something along that line.

Thanks for the tips I'll let you know what I find
Jeff/Illinois is offline   Reply With Quote
Old 05-21-2020, 09:43 PM   #16
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Checking an Ignition Ballast Resistor

You do not use an external resistor with a 1.5 ohm coil in a 6v system, how it was wired before is not relevant, it is not correct. There could be another issue as well, but the resistor in the circuit is sure not helping any! It is increasing the voltage drop (reducing the current flow in the circuit).

The under dash resistor was intended for use with a .7 to .8 ohm coil, it does not work with a 1.5 ohm coil.
JSeery is offline   Reply With Quote
Old 05-21-2020, 10:55 PM   #17
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by JSeery View Post
You do not use an external resistor with a 1.5 ohm coil in a 6v system, how it was wired before is not relevant, it is not correct. There could be another issue as well, but the resistor in the circuit is sure not helping any! It is increasing the voltage drop (reducing the current flow in the circuit).

The under dash resistor was intended for use with a .7 to .8 ohm coil, it does not work with a 1.5 ohm coil.
I will try the re-wiring soon that you suggested. What puzzled me was the 2500 miles or so I have driven this truck wired like that and it ran really well. When it died Saturday it was a slow death, like it was fuel starved. I feathered the gas pedal and played with the choke and made it about a mile before she went completely dead.

Jim Linder has been dealing with some health issues as we know, I was hoping to send the distributor over to him to have him check it out. I'll have to ring him up and see if he's up for it. He is about the best Bubba's Ignition rebuilt this dissy probably ten years ago. I'm thinking the points are boogered up by now and I don't have a way to set them if I put new ones in.

Last edited by Jeff/Illinois; 05-21-2020 at 11:43 PM.
Jeff/Illinois is offline   Reply With Quote
Old 05-22-2020, 12:51 AM   #18
JayChicago
Senior Member
 
JayChicago's Avatar
 
Join Date: Jan 2019
Location: Chicago
Posts: 711
Default Re: Checking an Ignition Ballast Resistor

"6.1V at the resistor on both ends."
That makes me think the resistor has already been jumped, has already been by-passed.

"Voltage drops to 4.2 V across the coil and holds at 4.2V to the condensor."
That has me puzzled. Shouldn't voltage on the distributor side of the coil give a voltage reading of 0 ? Isn't it going to ground through the points? Seems like there should be nothing to hold potential in that wire, is going directly to ground.
JayChicago is offline   Reply With Quote
Old 05-22-2020, 12:56 AM   #19
Tinker
Senior Member
 
Tinker's Avatar
 
Join Date: May 2010
Location: MN
Posts: 7,053
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by JSeery View Post
True, but was assuming it was a standard 1.5 ohm 6v coil. As flatjack posted, it is always best to check.

What flatjack said. 4 volts at the coil is best.


My understanding is it does matter how you wire the coil +/- poles.
Tinker is offline   Reply With Quote
Old 05-22-2020, 10:49 AM   #20
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by Tinker View Post
What flatjack said. 4 volts at the coil is best.
My understanding is it does matter how you wire the coil +/- poles.
Is there some confusion here? Voltage to a 1.5 ohm coil should be full system voltage, 6+ volts. You may be thinking of the voltage to an original distributor mounted coil.

I have never checked it, but the claim is reversing polarity at the coil results in about 80% loss of coil output. For a positive ground vehicle it should be supply voltage from the ignition switch connects to the (-) terminal and the (+) terminal connects to the distributor (points/capacitor).
JSeery is offline   Reply With Quote
Old 05-22-2020, 05:08 PM   #21
FlatheadTed
Senior Member
 
FlatheadTed's Avatar
 
Join Date: May 2010
Location: Auckland
Posts: 4,691
Send a message via AIM to FlatheadTed
Default Re: Checking an Ignition Ballast Resistor

Some can type coils state resister needed but thats for 12 volt ,remove the resister and its suitable for 6 volt ,but check the ohms ,you
may find the old school condenser is more reliable than some repoped ones ,some shrink tube , did you check if there was a spark across the plug ,Sound Fuel related to me ,
__________________
http://www.flatheadted.com


Flathead Ted brake Floaters ,
FlatheadTed is offline   Reply With Quote
Old 05-22-2020, 10:02 PM   #22
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by JSeery View Post
Is there some confusion here? Voltage to a 1.5 ohm coil should be full system voltage, 6+ volts. You may be thinking of the voltage to an original distributor mounted coil.

I have never checked it, but the claim is reversing polarity at the coil results in about 80% loss of coil output. For a positive ground vehicle it should be supply voltage from the ignition switch connects to the (-) terminal and the (+) terminal connects to the distributor (points/capacitor).
Today I had the time to by-pass the resistor under the dash, and did as you said, moving the ignition switch to resistor wire over to the 'out' side of the resistor so it follows the red wire directly to the neg. post on the coil now. Can type coil internal resistor measures 1.5 ohms at the coil.

I have 6.1V at the ignition switch and 5.9V at the negative post on the coil. I just don't seem to be getting anything out of the distributor. I'm figuring the points have arced or burned or something. The '36 started sputtering losing power, came out of it got about 2 miles and then quietly shut down.

First thing I thought of was fuel, the accelerator pump is working I'm getting gas to the carb, first thing I did when I got home was dribble a little gasoline in the carb and still couldn't get it to pop. This is on a Stromberg 97 that had a rebuild 2-3 years ago from a very very reputable guy, a Stromberg guru.

Anyway I'm more of a Model A guy flatheads are still new to me. When a Model A acts like this '36 did, it is points closing up about 90% of the time that is real common. Even a weak condensor on a Model A Ford will give you some power at the engine, just makes the A run weak. I just guess I'm prejudiced in that way of thinking, been around Model A's since 1971.

I hold the coil wire to ground and my wife cranks it and there is no spark. Put a new NAPA FA 54 condensor on no change (didn't have the facilities to have that condensor checked possible it is bad out of the box, Made in Mexico usually there stuff is pretty decent.)

Nothing wrong with the starting circuit this truck cranks like a new car really turns over.

I am going to call Jim at Bubba's and speak with him, after that I will get back on here and let you all know what happened. It has to be something simple I'll keep picking at it. I've never changed points on a flathead distributor, I am assuming you have to set them up on a Sun machine.

Thanks to all for the help and advice, it's greatly appreciated I'll be back..........
Jeff/Illinois is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 05-22-2020, 10:07 PM   #23
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Checking an Ignition Ballast Resistor

Hang in there.
JSeery is offline   Reply With Quote
Old 05-22-2020, 10:48 PM   #24
JayChicago
Senior Member
 
JayChicago's Avatar
 
Join Date: Jan 2019
Location: Chicago
Posts: 711
Default Re: Checking an Ignition Ballast Resistor

Your 4.2 volts on the distributor side of the coil makes me think there is resistance between the coil and where it goes to ground at the points. You could try this simple step before having to get into the distributor:

Your can type coil uses an aftermarket adapter on top of the distributor where the original coil was mounted. Adapter is easily removed. See if anything obviously wrong with the adapter. Remove the small wire coming from coil and clean that connection. Also clean the contacts on the underside of adapter where they make electrical contact inside the distributor. While you have it off, put your ohmmeter to it. Should get no reading (full continuity) thru the adapter.

Last edited by JayChicago; 05-22-2020 at 11:46 PM.
JayChicago is offline   Reply With Quote
Old 05-23-2020, 12:16 PM   #25
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by JSeery View Post
Hang in there.
Thanks bud, electronic ignition may be the way to go I'll read up more on that. Comments by people are good and bad like anything else. I've had a Pertronix on my '69 Mach 1 for probably 15 years and never ever had an issue. I HAVE read in Early V-8 stories of the front mounted dist. being kind of troublesome and it cost consumers back in the old days a bit of trouble and expense. Of course they had to wait until Henry died to change it out to a more modern type that we see in post 1948 flatheads.

Jay thanks for your suggestion I will give that a try too!

I'll let the Forum know what I find out again thanks for the help
Jeff/Illinois is offline   Reply With Quote
Old 05-23-2020, 01:02 PM   #26
JSeery
Member Emeritus
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 16,132
Default Re: Checking an Ignition Ballast Resistor

Sponsored Links (Register now to hide all advertisements)
I know very little about Pertronix use in flatheads, but understand they work OK with 12v systems but not so well on 6v.
JSeery is offline   Reply With Quote
Old 05-23-2020, 02:20 PM   #27
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,371
Default Re: Checking an Ignition Ballast Resistor

The front mounted distributor doesn't make it easy to troubleshoot on the early V8s thru 1948. The crab type maybe but the Helmet type not so much unless a person removes it and inspects the parts in there on the bench. A bad condenser can completely kill the inductance of the coil and not allow any spark at all. It just depends on the condition of it. Don't assume that it will still function an any usable capacity. Just replace it with a known to be good part and check for good spark. If the points are burned up then that would be a good indication that the condenser is/was bad since that's what protects the points from arcing. Many of the new replacement condensers are crap right out of the box. Setting up the helmet isn't too bad. A person just has to follow the Ford instructions. The condition of the flyweights, vacuum brake, and the rotor & cap parts can all be scrutinized & repaired as needed. If the ignition leads are very old and in poor condition, it might not be a bad idea to replace them. These units need maintenance & lubrication now and then to insure it all still works as it should. If the timing was already pretty close, the chances are pretty good that it will remain that way. Bolt the thing back on and test it.

Electronic ignition may be an alternative but a well maintained original system will give years of trouble free service on cars that are stored well and operated regularly. Echlin condensers are still decent parts when compared to a lot of others but they recently merged with Standard Motor Parts so the quality may be in question from what they used to be. The high dollar Vertex magneto condensers are out there but they aren't set up well for the helmet design distributor.

As I mentioned before, those can coil adapters can go to crap on you and it should be checked for contact and fit. The helmets work a lot better with their original coil installed but there were several different coils available in 1936 so it depends on which one will fit as to how easy it would be to find a good core to rebuild.

Last edited by rotorwrench; 05-23-2020 at 02:40 PM.
rotorwrench is offline   Reply With Quote
Old 05-23-2020, 07:41 PM   #28
Jeff/Illinois
Senior Member
 
Jeff/Illinois's Avatar
 
Join Date: May 2010
Posts: 2,787
Default Re: Checking an Ignition Ballast Resistor

Quote:
Originally Posted by JSeery View Post
I know very little about Pertronix use in flatheads, but understand they work OK with 12v systems but not so well on 6v.
I never thought of that. Looks like since I'm just staying with 6V POS ground as original I'll go back down that path.

Rotorwrench what you say makes good sense thank you
Jeff/Illinois is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 07:14 PM.