1966DartConvertible
Well-Known Member
What do they do? And do I really need them in my car?
My car is a stock standard '66 Dart 270 with a 170ci slant.
PS: I suck when it comes to electrical stuff
Syed
Newbie ques: What are Ballast Resistor and Voltage Regulator for?
- Thread starter 1966DartConvertible
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What do they do? And do I really need them in my car?
My car is a stock standard '66 Dart 270 with a 170ci slant.
PS: I suck when it comes to electrical stuff
Syed
The car's alternator will put out voltage relevent to RPM to a point, so it needs something to keep it in check and not toast the elecrtical system. The voltage regulator keeps voltage at a level that will keep the battery charged and not cook the rest of the electrical system. The ballast resistor is used because the ignition coil is designed to operate on less than 12 volts. The ballast resistor drops that voltage to whatever the resistance allows. I forget Ohm's law. It's something like for every ohm of resistance, "X" amount of voltage is dropped. I'm sure there are much smarter minds then I here, but that is it in a nutshell. yes, you really need a voltage regulator. The ballast is used for most factory style ignitions that are similar to a Mopar. There are plenty out there though, that are designed to see 12 volts so in their case, the ballast is not used. There are conversions you can do to the Mopar that do not use a ballast and some say is more reliable. THe GM HEI unit is one of those conversions.
67Dart273
Well-Known Member
Strocker's right
Some newer electronic ignitions don't use a ballast, but in "the old days," it was twofold
The system draws different current at idle than at high RPM, and the ballast was supposedd to mitigate that change somewhat, but when 12V cars came along it provided a SECOND function.
All 12V cars used a "resistor bypass" circuit. In the case of Ford/ GM it was an extra contact on the starter solenoid. On Chrysler stuff, it's the "ign1" circuit from the ignition switch.
This bypass circuit fed "hot" battery voltage to the coil during start, so that you still had a good spark during engine crank. When you let off the key, the ballast was back in the circuit.
Stroker's also right about the voltage regulator. If you take an alternator and bypass the regulator, and start the car, it may not charge much or at all when at idle. But as you increase engine RPM, the alternator voltage will just keep going up and up and up, until the battery is LITERALLY boiling. If the battery gets charged up, you can keep going up with voltage until lamps burn out.
Believe me, car manufacturers don't just throw parts on a car for fun.
Some newer electronic ignitions don't use a ballast, but in "the old days," it was twofold
The system draws different current at idle than at high RPM, and the ballast was supposedd to mitigate that change somewhat, but when 12V cars came along it provided a SECOND function.
All 12V cars used a "resistor bypass" circuit. In the case of Ford/ GM it was an extra contact on the starter solenoid. On Chrysler stuff, it's the "ign1" circuit from the ignition switch.
This bypass circuit fed "hot" battery voltage to the coil during start, so that you still had a good spark during engine crank. When you let off the key, the ballast was back in the circuit.
Stroker's also right about the voltage regulator. If you take an alternator and bypass the regulator, and start the car, it may not charge much or at all when at idle. But as you increase engine RPM, the alternator voltage will just keep going up and up and up, until the battery is LITERALLY boiling. If the battery gets charged up, you can keep going up with voltage until lamps burn out.
Believe me, car manufacturers don't just throw parts on a car for fun.
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