1931 Model A Ford Spark Issues

[brandontaub1]

     Hello everybody, I have been working on a non-running model A for a few months and she refuses to spark. I have diagnosed that there are indeed 6 volts going to the distributor coming from the starter coil. The distributor and coil are brand new, along with the wires which I have tested for continuity, they are also all connected up tightly. I have run out of troubleshooting ideas at this point beyond checking for bad connections and replacing the majority of old parts with new ones, any ideas? 

[Oregon Desert model 45]

clean the condenser connections.  New condensers procured from online Model A vendors are notorious for being junk.  A new distributor probably has the same questionable condenser.  There was as discussion over on Fordbarn with recommendations for a quality condenser.   

 

https://www.fordbarn.com/forum/showthread.php?t=332424

Are the points set correctly ? 

Every time I can't get spark from my A it almost always is due to the condenser

Edited November 20, 2023 by Oregon Desert model 45
edit (see edit history)

[Mark Gregush]

Could have oil on the points from manufacturing. Try cleaning the points. Which points are you using, modern or A style? Do you have the pigtail running from base to points plate? Do you have voltage to the points, do they spark when you break contact?

RE the suggestion to look at post on Fordbarn.com: There is a very active group in the Model A section on the site (maybe one of the better sites for Model A questions). If you have not, I would suggest going over there and take a look. 

[Pete O]

If you have an original distributor in the old girl, a known trouble spot is the short wire below the upper distributor plate that connects the lower plate to the stud on the points.  Old cracked insulation can short the voltage to ground before it gets to the points.  Also, look at the connector on the end of that wire and make sure it is not making contact with any part of the upper plate besides the stud on the points, or with the body of the distributor when the upper plate is installed. 

Edited November 20, 2023 by Pete O (see edit history)

[Oldtech]

Is it wired correctly? Power from starter to switch to coil?  Is it a regular coil or the armored cacle?

[Farmallregular]

7 hours ago, Oldtech said:

Is it wired correctly? Power from starter to switch to coil?  Is it a regular coil or the armored cacle?

On a model A the switch is between the coil and the points...that plus the armored cable to the distributor was Henry's way of keeping people from hot wiring them. 

 

Quick check, put  test light (not a meter) on the coil terminals.  One side should be hot all the time, the other side should pulse as the points open and close when cranking the engine.  Steady light on both sides while cranking indicates an open circuit between the coil and points (which includes ignition switch), no light on either side indicates no power to coil, no light on point side indicates a short to ground between coil and points.

 

Note that open and short circuits could also be the points themselves either not opening or not closing.

 

Repo condensers are another known problem area, although I believe they typically fail open.

 

Keith

 

Edited November 21, 2023 by Farmallregular (see edit history)