Thread: whats a ballast resistor

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whats the difference between a ballast resistor and a ballast resistor bypass???

The bypass he's talking about is the second post found on some soleniods. It is wired directly to the + side of the coil and provideds the full battery current to the coil during starting for a hottter spark and easier starting.

Personally, I have found that where I live in a warm climate they really arn't all that necessary. Back in my youth in the midwest when it's 20 degrees or below they make a big difference.

A ballast resistor is used to reduce charge voltage of system that is about 14 VDC to 9.6VDC. If you are running points and allow full system voltage to points it will make a hotter spark and work better than technology of points systems that was available. BUT it does so at a cost and that cost is reliability. IT WILL BURN points out much quicker and pit them. Now the original design was to allow full system voltage during cranking via the starter sol. and then when crank portion of key was released to the run side voltage or current goes through the resistor (either in the inline wire or earlier models used a seperate resistor) the early models were mounted on the firewall and looked like a white plaster looking rectangle about 3 inches long by 3/4 x 3/4 in width. All newer electronic systems HEI need lower voltage and already have higher output potential or 40 to 60 KV on secondary side. We used to put a toggle sw on dash to go around resister for that light to light demand and sw back to inline for cruisin in the old highschool days.

how did you hook the toggle switch up???

The toggle switch would have a wire on one side going to +12 like the batter terminal, and the wire on the other side would connect anywhere between the ballast resistor and the distributor.

76 is right on, for wiring. Do this only with the true old coil and points set up and only if willing to replace points more often. Do not bypass with HEI or othe electronic ignitions as it will cause failure!!