The old truck won't start. No fire at the plugs. I filed the points and they spark when the engine turns. All plug wires are well connected. Rotor and cap look good. I suspect condenser. Is that the most likely problem?
This is why I scoff when people install a disturbutor in their T because it's "more reliable".
Check for power on your ballast resistor, Also check the voltage going into your coil and coming out. Should be 12 in and around 3 or 4 at the points if I remember right. Probably due for a complete ignition rebuild. I would rather have an old points and condenser set up than theses new computer set ups we have today. Let me know the year and engine and I will send you the spec's
If the points spark you have current in the coil primary. Even with a bad condenser you should have a weak spark at the plug wire.
Probably a bad coil (open secondary).
Check to see if your getting a spark at the coil. With the switch on and the coil wire close to the block open and close the points with a screwdriver to see if your getting a fat spark. if yes, check point gap, if ok scrape rotor and cap contacts with your pocket knife to remove any corrosion. If not, do what Will says.
1951 B-3-C. The wiring diagram in the shop manual doesn't show anything labeled as a ballast resistor. What is that?
The engine will usually run with a bad condenser, but the points won't last long due to arcing. If you see sparking at the points, it would certainly implicate the condenser. I assume that you regapped the points after you filed them.
Take the coil wire off the distributor, pop off the distributor cap and lay it aside, then verify that the points are closed. Turn the key on and open the points by hand with the end of the coil wire held close to a good ground. You should see a bright blue spark when you open the points. If you get a weak, yellow spark or none at all, then either your primary voltage is low or the coil is suspect.
If you get a strong spark at the coil wire, but not at the plugs, then the problem is in the secondary circuit - start looking at the distributor rotor and the inside of the cap.
(Message edited by cudaman on October 01, 2016)
There should be no ballast resistor on a 6V system.
It could be the condenser but usually they go slowly and act like carburetor problems.
My vote would be for new plug wires. Or at least a new high tension lead from the coil to the distributor. That fixed my 8N tractor after I had checked all of the things you mention checking. Too cheap not to try.
Broken ground wire on distributor plate to housing
plug gap> .035
timing > tdc
valve clearance intake .010 hot exhaust .014 hot
point gap> .020
And no resistor on your truck.
Time out while I charge the battery. Too much cranking ran it low.
Check continuity from the center to the outside on the rotor.
My T started having issues with the rotors lost continuity at that point. It had the original rotor for some reason it was sunk under epoxy from the center to the end. The 6.00 replacement was solid metal at that check. It runs good again. An inexpensive adjustable spark tester is a handy tool.
I'm on the bad rotor, cap, and/or coil wire team. Seems like the old Flathead six Mopars put up with just so much extra ignition resistance, and then one day, especially after being damp, no start.
It's hard to understand it until you see it but if your starter is dragging it might suck so much power you have none for ignition!! Bud in Wheeler,Mi.
Are you getting excessive sparking at the points?
If so that indicates a bad condenser.
A coil requires the discharge of a condenser to develop a healthy spark.
Bud has a point. Also be certain your points are actually breaking. Distributor Cam may be worn.Also bushing in top of distributor may be worn out, allowing the shaft to slop around, keeping points from actually breaking.
Jim has a good point about the worn distributor bushing, I had that happen on my first car (a 1972 Dodge Charger with a 318 V8). The upper bushing got so worn that the points wouldn't open, the distributor shaft just moved around in the wallowed-out bushing.
A bad bushing would not fail all at once, It would give ample warning by the engine running rough. I may be wrong but I had the impression that the problem happened over night.
Will, maybe, maybe not. The old Chrysler products Flathead sixes ran so smooth a little rough running may not be noticeable. Steve, also make sure the rubbing block, I call it, on your points is not shot.
I put a new rotor cap on my farmall in the fall last year. Mowing in the spring and it quit. I wasn't ready to quit or finished. Worked on it for hours. Tried coils , points , condenser , I knew it wasn't rotor because I just replaced it with plugs points ect... Long story short an old tractor me mechanic asked if I saved old rotor cap? Why yes it still worked . I can't throw stuff away. He said to throw the new one in the trash and put the old one back on. Didn't turn over once and it was running.
A bad plug wire caused it to arc through the rotor cap.
That spark will go to ground the easier way which was the cheap new part.
Hope you find the problem hope this helps
You might have a resistor and if you do it'll resemble the picture. It will be on the + wire going to the coil. Are you neg. ground or pos? I know some Chrys were pos grnd. (I ask because your coil will be wired "backwards" if you're pos grnd). Your coil might have a built in resistor. It'll say so on the body if it does. OK, points spark when cranking so power is getting that far which is actually as far as the batt voltage will go. Cleaned/adjusted the points so we're probably down to a condenser or coil gone south. Honestly, I haven't seen many condensers go over the years so I'm leaning on the coil based on what you've posted.
As posted before, a '51 Dodge does not have a ballast resistor. It is also six volts, so don't expect 12 volts going anyplace. It was also originally positive ground.
It comes with an ignition coil with a built in resistor.
You must use the right coil. A '66 or older VW coil will work in a pinch.
A VW coil would need to be connected backwards as the Dodge is positive ground.
Those old Chrysler machines had a copper strap instead of a wire going from the condenser body to the points.
A fifties Ford condenser can be connected at the coil, on the dist. Side. It must be grounded..
As Bud points out, starter draw can also cause starting failure.
A starter draw gauge is cheap. Get one that you hold against the battery cable.
That old turkey should show draw 175 amps.
If it draws more than 200 you will have hard starting.
If it draws 300 you gotta rebuild the starter...now!
Steve, What was the final verdict? Did ya get her to go yet?
Totally unrelated, but MY Dodge failure involves me being too busy to
get mine dug out of the back of the shop or having the time to go drive
Burger, Anytime that old Mopar is in your way just let me know. I will come and get it! Nice ride.
Mark got it. Condenser. https://youtu.be/NvVHSBgnaxE
It makes a good storage shelf for all sorts of errant shop things !
Hi, Steve. I was gonna suggest condenser. They can fail in all kinds of strange and unpredictable ways. Plus, the ones they make these days have about the life expectancy of a mayfly.
Ballast resistor? Many vehicles with six volt systems use them. Not sure about your Dodge. If it has one it will look like Charlie B's picture above and is probably somewhere on the firewall.
Glad you got 'er going. Bob