Ballast Resistor in TR4

[CJG]

Hi Everyone,

 

I intend to fit a Pertronix "Flamethrower" ignition coil to my 1962 TR4 (positive earth). The car is currently still fitted with its original (very leaky) Lucas coil. Does anyone know if the car is fitted with a ballast resistor, and if so, where should I look for it - apparently I have to remove it for the coil to work properly. P.S.: the car is fitted with an Ignitor electronic ignition module.

 

Thanks in advance.

 

 

CJG

[Brian-Northampton]

I'll let others clarify more, but I didn't think that ballast resistors came into common usage until the 70's. Besides, you would have had to bypass any ballast resistor for the ignitor electronic ignition if you had one.

 

I believe the easiest way to check (from memory) is to measure the resistance across you old coil, it should read about 3 ohms in a non-ballasted setup and about 1.6 ohms in a ballasted setup.

 

Your new coil should be 3 ohms. So if they're both the same (give or take) then you'll be just fine.

 

Cheers,

Bri.

[ianc]

Unless someone has been playing silly games, your TR4 will NOT have a ballast resistor.

If you are sticking with positive earth, make sure that your Pertronix device works with that - most electronic gadgetry expects negative earth.

Ian Cornish