Topic: 1946 Ford coil replacement


JoanRebholz    -- 07-18-2013 @ 6:44 PM
  Bought a coil from a reputable dealer, but after 20 min it heats up and quits. Need opinion on 1946 Ford coils, where and what to purchase or where to get rebuilt.
(I'm asking this for a friend)


fla48    -- 07-18-2013 @ 8:00 PM
  Have Skip rebuild your coil. He does an excellent job of rebuilding them. Also make sure the condenser is good. Also if it is not hooked up properly you can toast the coil (don't ask how I know).


supereal    -- 07-18-2013 @ 9:02 PM
  Is your car converted to 12 volts? If not, is the ignition resistor on the inside of the firewall in place and in the circuit? Standard stock coils are designed to operate with about three volts input. Anything higher will cause the coil to overheat, and eventually be destroyed. If the input voltage to your coil is correct, it is defective and should be returned to the vendor.


Old Henry    -- 07-18-2013 @ 10:45 PM
  Because there are other ignition components that can fail you might want to check your coil resistance when you think it has failed to see if it's really the coil or maybe something else. The attached diagram shows what the resistance should be for the primary and secondary circuits.

Old Henry
(The older I get, the better old looks.)


supereal    -- 07-19-2013 @ 8:39 AM
  A resistance test with an ohmeter will tell you if the windings are intact, but because the windings can't be separated, any breaches in the dielectric won't show up, nor will the reactance of the coil be shown. That is one reason the coil "testers" of years ago were not helpful, but they sure sold a lot of coils! If you want to test the resistance, do it first with the coil at room temperature, then put it in the oven until it is almost too hot to touch, and compare the readings.


TomO    -- 07-19-2013 @ 2:43 PM
  I have 3 type of coil testers and they all have their merits and faults.

The first one is from the early 1950's. It consists of a spark gap, meter, contact points and a camshaft driven by an electric motor. It is designed to test the coil like it is used in a motor. It doesn't have any provision to heat the coil.

The second one is from the late 1970's and was made for Snapon. It consists of a vibrator and a spark gap. It has a provision to heat the coil and test the condenser in the distributor. You can overheat a coil with this tester and destroy it.

The 3rd style is just a meter that will read the coil output and is pretty useless.

The final test of any coil is how it performs on the car.

Tom


42merc    -- 07-19-2013 @ 3:04 PM
  If it is a show car have the original rebuilt by Skip. If it is a driver, go to NAPA & buy a 6 volt coil for a 1950 Ford, bypass the '46 resister so you have a constant 6 volts to the new coil & everything will work just fine. Don't worry about the points. They will be OK.


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