Monday, September 28, 2015

Ditching the Ballast

If you're an avid follow of this blog, and let's face it, who isn't?!  Then you'll remember that back in this post I had a bit of a meltdown issue with the ballast wire. You'll also remember more recently in this post, I fixed everything with a new ignition wire and a new ballast resistor. All should be good under the hood, however I've noticed that the ballast resistor is getting rather hot to the point of concern. So hot in fact that it's too hot to touch.

So I've decided that the ballasted system is too annoying and I'm converting to the simpler non-ballasted system.
Ballasted Setup.

Because of the work I've already done replacing the resistive wire with a new ignition wire in the latter part of this post, the job of converting the ignition from a ballasted to a non-ballasted system is now going to be fairly straight forward affair.

After the battery was disconnected, the first thing to change is the coil, currently I have a Lucas DLB110 ballasted coil fitted that is designed to run at a lower ballasted voltage. If I simply fed this with the non-ballasted 12 volts instead of the 6 to 9 volts it would be expecting, I dare say it would eventually either just stop working or melt as it would be carrying almost double the power it's supposed to. This is best explained in this post here where I actually crack open a full fat can of mathematics on the subject.

So it's out with the old DLB110 ballasted coil.

The replacement coil is a new non-ballasted Lucas DLB105 that runs at 12 volts. After a quick scout around the internet, one was purchased from eBay and promptly delivered shortly thereafter. The good thing is that they are generally a little cheaper to purchase than their ballasted counterparts.

Hello new Lucas DLB105 non-ballasted 12 volt coil.

As the name would suggest, a ballasted system needs some kind of ballast, which is usually found in the form of a 'special' pink/white 1.5 ohm resistive wire that runs from the switched live to the positive side of the coil.  As mine had melted, I replaced it with a normal white wire along with a 1.5 ohm resistor as the ballast.

So the next step towards a non-ballasted system is to remove the ballast, so it's curtains for the resistor as it has to come out again.

So once the resistor was out and the coil had been changed, the next thing is to take the new white ignition wire (that was put in place of the resistive pink/white one) and attach it to the positive side of the coil to feed it with 12 volts.

Coil Swap
New white wire to the positive side of the coil.

The very last job to do is to remove the yellow wire that comes up from the solenoid on the starter motor. To be honest, it could be left there as all it does it feed the coil 12 volts when the engine is being started, but as a non-ballasted system runs on 12 volts, it's now effectively redundant.

Unplug me!!

For completeness, and to avoid future confusion, I also clipped it off the coil.

With the battery reconnected, a quick turn of the key soon fired up the engine and proved that all was still well. So that's that, I now have a non-ballasted ignition system, it really is that easy!! I just hope that a simpler system will lead to fewer problems.

This turned out to be one of those jobs that sounded harder than it actually was, once you learn and understand the differences between the ballasted and non-ballasted systems, it becomes pretty easy to convert from one to the other.

Even if I hadn't carried out some of the rewiring work in a previous post, it's still a pretty easy conversion:

  • Remove the ballast which will either be a pink/white resistive wire, or an actual resistor.
  • Replace it with a white wire, capable of handling the amperage. (I went with 30 amps which is way too much, but better too much than too little!!
  • Change the coil from a ballasted to a non-ballasted
  • Disconnect the yellow wire that comes up from the starter motor solenoid.

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