resistor wire

ChrisCJ7 · #1 (**permalink**) 07-20-2003, 08:00 PM

I'm in the middle of a Ford Duraspark / TFI ignition upgrade. The wiring schematic I'm working from shows the use of a coil-to-ignition switch 'resistor wire', but states it may not be needed.
What is the purpose and function of the resistor wire ?
How do you know if the resistor wire is needed or not ?
Chris

TerryMason · #2 (**permalink**) 07-20-2003, 08:00 PM

Is this just the adapter for the new coil, or is this a totally seperate wire. I had to make an adapter to go from the stock to the TFI coil.

Terry

JRUK · #3 (**permalink**) 07-20-2003, 08:00 PM

Terry,

He's not referring to the coil wire.

This resistor sits in line in between the ignition switch and the coil. When starting the engine the coil will get the full 12V supply and when the ignition key is in the run position, the voltage gets reduced by this resistor (1.35 Ohm normally).
The switching between resistor/non resistor is done by the starter solenoid. In the start position this resistor get by-passed.

This resistor should be there by default and is most likely a resistor wire.

Just leave everything as is and connect your new coil up normally. Some even suggest that the TFI coil needs 12V at all time, so if the engine doesn't run right you might want to take the resistor out.

Rene