Thread: what is this wiring part

looks like a ballest resistor for the coil my 2.6lt 6 doesnt have one do you have a 4 cyl maybe someone with a 4 can help more, as long as the wires are not earthing out on the bracket if shouldnt be a problem If the connection is earthing out bend the terminal a little so it doesnt make contact does the car start and run as it is?

Yes everyone is correct. It is the ballast resistor, it drops the voltage to the coil to 7 volts.

There should be a 7 volt coil and at one end of the ballast resistor there is a 12V ignition feed wire, at the other end of the resistor there should be two wires, one going to the coil and the other should go to the starter motor cable on the starter solenoid.

(The wire going to start, is to by-pass the resistor and feed 12V to the coil which when the starter motor is cranking is only about 7V so the engine gets full spark and starts easily.)

Diana

As everyone says, it is a ballast resistor. These were not standard on either the four or the six, but should work, provided it has a coil designed for use with a ballast resistor*. If either terminal is shorting to earth, there will be no ignition. If the 12v side is shorting to earth, there may be other wiring damage!

John

* Ballast resistors and low voltage coils are an idea from cold climates and particularly 6v electrical systems, that carried over to 12v electrical systems where inadequate batteries or wiring resulted in starting problems in cold weather. The idea is that by having the resistor shorted out during starting when the battery voltage is low due to the cranking current, you get a better spark than you would otherwise be able to get without having excessive points current when voltage is up to the normal 13.8.

Looks like it has a Holden engine so a ballast resistor is correct.

How did I know? Rocket Red dipstick fingergrip in bottom right corner!

Bob

Thanks everyone, and Bob gets the door prize for picking the Holden donk. It was originally a rover 6.

The comments have now prompted more questions, as quiet often the vehicle is hard to get started and sometimes doesnt even kick, but then 2 minutes later will fire. Could this be a problem around this so called Ballist Resistor? AND, do I even need it? can it be bypased or is there a better solution for the 186 powered Series3.

thanks again everyone.

Jim

As stated, it is correct for a Holden engine. Loose or sometimes shorted terminals on it will cause the problems you note, but these could also be caused by poor contact condition in the ignition switch, for example, or any other intermittent ignition fault.

You can operate this engine without the ballast, provided you replace the coil with one that is designed not to use a ballast, but unless either the ballast or the coil is faulty, you are unlikely to notice a difference, and if the ballast is faulty, it is probably cheaper to replace.

Replacing the entire system with electronic ignition is probably easy and will give a better and trouble free ignition system, but really, the original system, properly maintained is quite reliable. (and if you have, for example, a dicky ignition switch, it will still be unreliable!)

John

Originally Posted by Jimmy

Thanks everyone, and Bob gets the door prize for picking the Holden donk. It was originally a rover 6.

The comments have now prompted more questions, as quiet often the vehicle is hard to get started and sometimes doesnt even kick, but then 2 minutes later will fire. Could this be a problem around this so called Ballist Resistor? AND, do I even need it? can it be bypased or is there a better solution for the 186 powered Series3.

thanks again everyone.

Jim

Hi Jim,

Yes, you need the ballast resistor with the correct coil - they usually have a label "Use with Ballast Resistor". Some vehicles incorporate the resistor in the wiring harness so it is not particularly visible.

A 7 Volt coil will run without a ballast resistor and it will work for a while and then fail - sometimes with catastrophic results. The top of the coil may blow out and boiling oil will spew all over the engine and can ignite. Once had to do a ninja leap when we lifted the bonnet to investigate a "hard to start" 202 engine. You would not want your face over one if that happened.

Bob

Ballast reistor, just buy a 12V coil and be gone with it,I also thought Ballast resistors dropped the operating voltage to 9.6V after cranking, no that it matters if you run a 9.6V coil on 12V permanently they cook, explode and **** the tranny oil everywhere, learnt that when I was 14 on Datsun 1600 paddock bomb