Anonymous-0

Well-known Member
I have a ford 2000 3 cyl tractor 1965, It has a 12 volt ign system but does not have a resistor in the wiring before the coil. Does the coil have a built in resistor? The reason I'm asking is the point are badly burned. Thanks Mike
 
The original configuration was a resistance wire, not a resistor. The resistor wire was a piece of wire that had a higher resistance than normal wire and it had several lengths folded up on itself and then it was covered with an insulating material, so it looks like a much thicker wire than the rest of the harness. If you follow the primary wire from the coil it should be fairly obvious if it is still there.
 
sean gave you good info on the resistor wire.

many times it gets removed and a native 12v coil gets installed ( or not ).

pitted points can be a bad condensor as well
 
Ditto what has been said about the HEAVY wire,
and It should run from the coil under the battery base to the harness. If you clean it off it has 'resistor wire' printed on it.

The coil should also say 'external resistor required' OR 'internal resistor' on the case.

The burnt points, however, are not a function of the resistor
but of the condensor as has already been stated.

In simplistic terms, the points are simply a switch opening and closing a circuit,
and the condensor is there to suppress the spark as much as possible.

.
 
I checked the wiring harness, this tractor has no resistance in the wire from the ign. switch to the coil. The color of the wire matches the wiring diagram. So I was wondering if they may have used a coil with a internal resistor. The wiring diagram does not show any resistor in the circuit.
Also if you do not have a resistor in the circuit to lower the voltage, it will burn the points up no mater the condition of the condenser. Thanks Mike
 
The 1965-1975 thousand series tractors all came from the factory with the resistance wire. None of them came with a coil that was designed to not require an external resistor. But who knows what has been changed on yours since it left the factory? When I got my '73 4000 about 7 years ago it had no resistance wire, and instead it had a large ceramic ballast resistor that looks like the same one that was on the Oldsmobile 455 V8 that was in my 1972 Jet boat.

Not having a resistor will not burn up the points. As has been stated by others, the condensor protects the points.

The lack of an external resistor on a coil that is designed to use one will cause higher current through the coil than the coil was designed to handle and so it will run hotter than it should and eventually the insulation in the coil will break down and the coil will fail. It may also cause the condensor to fail, and once the condensor fails the points will burn up.
 

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