restoring done.....no spark

[Anthony Ellis]

All the anticipation, she is a thing of beauty, lets hear her run.
Nothing. It is a front mounted distributer 1947. I have replaced
the 12v to 6v resistor now I am getting 5.81 volts to the top of
the coil, which I tested and is good. I put my ohm meter across
the pig tail and the high tension contact going to the rotory arm
and got 8.53 ohms. the setting of my gage was on the 20k.
This was done with no power to it. I then replace the condenser
because still no spark. Then the points and rotor arm. Then the
plugs and wires. I replaced the ammeter gage but I don't think
that has anything to do with it. It has been two days (8 hours)
and several trips to Tractor Supply Comp. I am stumped! Tony

 

[Jimmy in TN]

I had the same problem, turned out to be the coil, I already had 2 but bought a new 12v coil at NAPA, problem solved. hope this helps, Jimmy in Tn

 

[JMOR]

(quoted from post at 18:14:48 01/25/09) All the anticipation, she is a thing of beauty, lets hear her run.
Nothing. It is a front mounted distributer 1947. I have replaced
the 12v to 6v resistor now I am getting 5.81 volts to the top of
the coil, which I tested and is good. I put my ohm meter across
the pig tail and the high tension contact going to the rotory arm
and got 8.53 ohms. the setting of my gage was on the 20k.
This was done with no power to it. I then replace the condenser
because still no spark. Then the points and rotor arm. Then the
plugs and wires. I replaced the ammeter gage but I don't think
that has anything to do with it. It has been two days (8 hours)
and several trips to Tractor Supply Comp. I am stumped! Tony

Anthony, I will assume that there is some error in reading or interpretation of scale, since the 8.53 ohms you report from HV tower to pig tail is FAR too low.....expect ~5,000 to 20, 000 ohms for this secondary winding resistance. You report 5.8v to top of coil. This is with points closed, I assume? Too high, but not totally unreasonable, for now.(work that later) Now, what does that voltage reading become when points are open? Expect battery voltage.
If not seeing the change from 5.8 to 12 as points open and close, then the coil pig tail may not be seated in concave screw properly (stays high v all the time, or if stays low v @ 5.8 even with points open, look for pig tale short to distributor case or condenser wire terminal shorted to case.

FYI
The primary coil terminal to pig tail should be in range of 0.5 to 2.5 ohms.

 

[Tom N MS]

Power to top of coil but no spark....Did you check to see if the points are grounded to the case even when open? If so, not good, and means most likely shorted out where the concave screw goes through the copper strip(where the coil spring contacts) that concave screw is insulated(suppose to be) from the case and that insulator is famous for breaking down...or maybe you let the condenser wire connector twist around and ground out against the case......points set on .015 and open and close like they should. Copper strip could be broken...check these things and let us know how it runs......I'm betting it is one of these things

 

[Tom N MS]

Are you sure that the other coils are bad? Sometime when you have a spare few minutes, try one of the other coils again with the cork gasket removed from under the coil..Lots of times the spring contact on the coil does not contact the concave screw as it should..With the gasket removed it will contact the screw...with gasket removed, fold a piece of paper to put under the coil bail so the bail will still hold the coil down tight..If it cranks and runs like this, then the pigtail needs carefully stretched so you can put the cork gasket back under the coil but still let the springy pigtail make contact....

 

[Bruce (VA)]

In addition to what the others are asking......what is a "12v to 6v" resistor? You should only have one resistor in the circuit if the tractor is 6v & it's not a 12v to 6v resistor. It should be p/n 12250. It should measure about .3 ohms cold.

The picture shows how to check coil resistance.

Lastly, I've never had much luck w/ TSC ignition parts.

50 Tips

 

[Anthony Ellis]

Thanks for all the new things to try. I hope that some day I can be as knowledgeable and helpful as you all. I will try these ideas tomorrow.

 

[Ed S.]

(quoted from post at 19:46:27 01/25/09) Thanks for all the new things to try. I hope that some day I can be as knowledgeable and helpful as you all. I will try these ideas tomorrow.

If it makes you feel any better, I had my distributor on and off my freshly restored '50 frontmount three times before I got everything lined up right. Had the pigtail grounded the first time, and seems like something else shorted out the second. I finally assembled the coil to the distributor off the tractor and installed as one assembly - hard to snake it in place, but less chance of knocking something out of whack trying to assemble on the front of the engine.

es

 

[Jimmy in TN]

Anthony, another thing I had to do The pig tail was shorting out on the bail like thing that holds the pionts plate down,I cut out a small piece of plastic out of an old credit card and put it between the bail and the pig tail,it was so close I like to never found it , I took my dist.out more than a dozen times. Jimmy

 

[JMOR]

Some places to look.

 

[Anonymous-0]

Lets go back to basics.Changing all the ignition parts is a costly way to get the spark back.Turn on ignition and press starter button.ammeter should wiggle back and forth if points are opening and closing.A steady 4 amp discharge says you have a short inside the distributor.No discharge says you have no power to the coil or the points are not making contact at all.Oxides can form on point surfaces that insulates.Clean the points...No need for expensive meters yet.Your reading of 8 ohms on the secondary is way off.8000 is more like it.A coil can have proper readings and still fail to produce a spark.The Ford front mount dist can be tested on the bench.a 6v lantern battery can be used,forget the resistor for now.Make a spark gap from the dist body to the coil hi tension terminal,Now set the points to open position.Connect your battery, one wire to the frame the other to the coils top terminal. Polarity dosent matter.Take a small screwdriver and short the points a spark should happen when when you remove the short.The last time I told some one on this forum to quit being a parts changer and learn how a simple ignition works he called me an idiot.Makes me laugh,I started working on engines in 1950 and worked in auto service and for a JD dealer until I smartened up and went into electronics.

 

[Ed S.]

Those pics are keepers, JMOR - thanks!

es

 

[JMOR]

(quoted from post at 08:39:46 01/26/09) Lets go back to basics.Changing all the ignition parts is a costly way to get the spark back.Turn on ignition and press starter button.ammeter should wiggle back and forth if points are opening and closing.A steady 4 amp discharge says you have a short inside the distributor.No discharge says you have no power to the coil or the points are not making contact at all.Oxides can form on point surfaces that insulates.Clean the points...No need for expensive meters yet.Your reading of 8 ohms on the secondary is way off.8000 is more like it.A coil can have proper readings and still fail to produce a spark.The Ford front mount dist can be tested on the bench.a 6v lantern battery can be used,forget the resistor for now.Make a spark gap from the dist body to the coil hi tension terminal,Now set the points to open position.Connect your battery, one wire to the frame the other to the coils top terminal. Polarity dosent matter.Take a small screwdriver and short the points a spark should happen when when you remove the short.The last time I told some one on this forum to quit being a parts changer and learn how a simple ignition works he called me an idiot.Makes me laugh,I started working on engines in 1950 and worked in auto service and for a JD dealer until I smartened up and went into electronics.

Mr. 36coupe,
Just when the process was coming into it's own with computers & automation, you are saying don't do it. What now? Actual troubleshooting?!

 

[Anthony Ellis]

I just tested the two coils that I have one registers 1.5 and the other 2.8, is one a 6v and the other a 12v?

 

[Anthony Ellis]

I guess credit cards are good for something! I am about to go out and try for spark. I will keep you all posted.