ballast resistor is jumped - why?

[Deleted User]

Okay, a new day and a new question. Just noticed the ballast resistor on the '54 Jet (on the firewall) is jumped. There's a wire attached on one end that is attached to the other end. It's a new wire that some previous owner added.  It's evident this was done very recently.  I purchased the car last month and just noticed the wire.

Why would this have been done? Will this ruin my coil? 

Thanks!
Mike

Ol racer

FYI

Perhaps the coil they installed has an Internal Resistor....

Geoff

 Are you on 6 or 12  volts?

lostmind

Could be the resistor is burned out and they jumped it to get it to run. Remove it ant look at the

resistor coil , or check it with an Ohmmeter.

Glowplug

Remember;  ignition resistors are in place to compensate for the difference in latent coil resistance. If the coil in use has an internal resistor the external resistor is not needed. If the coil in use does not have an external resistor the coil will overheat and the result will be a defective coil. 

Symptoms of a  over voltage to a conventional coil include high speed miss and occasional back-fire.  

The following link has a good explanation of the purpose of Ballast Resistors in automobile ignition systems.

Park_W

Or they just decided to push more voltage to the coil.

tigermoth

does a 6v system use a ballast resistor? regards, tom

PaulButler

It could just be that the ballast resistor went awol and this was the quick fix. Done that more than once myself

Geoff

Yes, 6 volt systems did use ballast resistors, but not all.  On some pre-war cars there was a resistor  connected to the input terminal of the distributor.   The coils on these models were 4 volt rating.  the principle was that when the car was cold started then full voltage would flow through the coil, giving a good hot spark. then as the resistor heated up, the resistance increased, and cut the voltage to the coil, and give longer point and condensor life (theoretically).   If your car has an original coil, then it should also have the original resistor.  Otherwise use a standard 6 volt coil.  If you cannot get a 6 volt coil, then use a 12 volt coil designated for use with an external resistor (ballast),  but you do not use a resistor with this.  it will work fine.   Some cars (but not Hudson as far as I know) had a bypass switch on the solenoid or ignition switch which provided full voltage to the coil on starting.