Ferguson TE-20......Ignition Problems

Hoping someone out there can help me as I am completely at a loss for what to do!

'48 Ferguson TE-20, 12V negative ground system with a newly installed alternator, new wiring, new points, new condenser, new distributor cap, new plug wires, new coil. I cannot figure out why it is not firing. Here's what I've tried so far:

1. verified the points are opening properly and I have current through the points as it will spark when the points open, also verified the gap setting and as noted above the points are new
2. pulled the primary ignition wire from the center of the distributor and held it close to a ground on the engine while cranking the engine....no spark from the coil
3. verified I have a full 12V at the positive side of the coil before cranking the engine
4. verified that the current flow through the coil primary windings is interrupted by the opening points so that seems to be working correctly
5. noticed a considerable voltage drop at the positive side of the coil while cranking so I tested the impact of that with a direct wire to the positive side of the battery to the positive side of the coil to get full battery voltage to the coil while cranking the engine....still no spark
6. replaced the coil (iternal resistor type, no ballast resistor).....3 times......still no spark
6. battery has a solid 12V and is not weak

I'm completely out of ideas of things to check as to why I have no spark. Any help or ideas of what to do would be greatly appreciated!

Larry

One thing for you to check. On the one I had there was a wire on the side of dist. I cannot
remember if it was fastened on with a screw or went into the dist. Mine was shorting out on the
dist boday. I added a piece of 1/4 tubing over it and it worked

Pull the distributor cap off and rotor etc. so you are at the points. Hold the center wire from the cap close to the block and open the points by hand. You should get a spark to the wire when you do that. If you do then the rotor or cap could be bad even if it is new

possible bad condenser, new ones are not necessarily good, put your old one in and check, old has a good method listed to c heck

Is your cap contacting the rotor? Like maybe the carbon is gone?

At this point, yes check out the cap & rotor carefully...

The new cap has a carbon element that is supposed to contact the rotor and it is in there where it's supposed to be along with a spring underneath it so that should put a little pressure on the carbon to keep it in contact with the rotor. How would I check to see if is making contact? It would have to be lined up perfectly with one of the pins for a cylinder and then check for continuity. Does the rotor come into physical contact with the cylinder pins on the distributor cap or does the spark jump across a gap?

I checked the old condenser with any ohm meter and the resistance steadily went up as the condenser charged. Did the same thing to the new one and it checked the same way so I am assuming they were both good. I have had condenser issues in the past with points type ignition systems and it was a grounding problem inside the condenser can so if this was happening the current would not stop when the points opened.

Did that.....no spark.

Everything I've tried indicates a bad coil but after three new coils I'm not convinced it's a coil issue. My luck is not the greatest in the world but what are the odds of getting three new coils that are bad?

I had the exact same thing to happen shortly after I purchased the tractor and had to "rebuild" the connection bolt that goes through the distributor to keep it from shorting out. Having been down that road I have checked that a few times and eliminated it as a possible cause.

How were you checking for "interrupted current" at the points? I use a test light, one side on the distributor low-voltage wire, one to ground. Light goes off when points close, on when open, flashing while cranking. A dwell meter gives you the same info and quantifies it, but you have a go-nogo situalion so not presently necessary. Had a co-worker with an old Chevy once, replaced every part inside his distributor before I suggested he make sure it was actually turning. It turned out to be a timing chain.

Clean the points!

Did you see a spark at the points when you did that test I told you about?? If you did not then your not getting power to the points and the insulator going into the side of the distributor maybe bad and shorted to ground and that will stop a spark also. BTDT on more then one tractor

I used a volt meter.

Had a spark at the points so I have power through the coil primary winding.

If you had a spark at the points the coil should fire every time you open the points. Only way you cannot have spark/fire out of the center wire of the coil when you open the points is to have a bad coil and coils do not just go bad out of the clear blue