do i need the ballsat

I have a mallory dist converted to breakerless and want to replace the stock coil i had to use with the accel 8140 that was in there before it died
do i use the ballast resistor that's in there now and was with the accel coil.
or by pass it
chris

 

What is the voltage in the coil wire with key on and no ballast resistor in place? I ask because if your original wire harness is unmodified, there is already resistance built in to the coil +12V feed wire. If you're not sure if the original resistance wire was removed or not, check with a voltmeter and report back.

The next step will be for you to tell us exactly which Mallory and other aftermarket parts you're running. If you don't have the original instructions for the breakerless setup (which will tell you about using a resistor or not), we'll see if we can find them on the web. We need to know what to search for first; part numbers, etc.

The more detail you provide the better the chances of getting good advice.

Devon

 

Will do
thank you Devon
:TU:

 

Mallory dist. part # 4764301H with 2092m cap and rotor
Mallory 6100M High Performance E-Spark Replacement Module
Mallory 29351 High Performance Active Power Filter
Mallory 700 High Performance Ballast Resistor
Mallory 938 8mm wire kit
Bosch platinum plus 4009 plug
http://www.taperformance.com/proddetail.asp?prod=TA_1235P (carb and intake setup thatcame on the car when i bought it)

1975 350 head ID 1248452 F/30

key in on position
11 volts to coil with ballast unplugged
5 volts to coil with ballast plugged in

let me know if you need anymore info

 

Good info.

First of all, the Mallory Unilite Distributor must have a resistor in place, either the factory resistance wire, or a +12V source plus ballast. See http://prestoliteperformance.com/Po..._wiring_diagram_test_procedure_1214M_0000.pdf

What's puzzling is that you tested +11V on the existing wire, which is lower than battery voltage, but not as low as I was expecting with a factory resistance wire. If you run the separate ballast resistor, it's going to want to see full battery voltage, so you need to check into that next. I'm assuming if you test the battery directly you're seeing over +12V, no?

Anyone got a voltage reading they can share on a system with the factory resistance wire in place for comparison? I think the +5V seen here with the existing wire (whatever it is) plus ballast resistor means too much resistance, would like to confirm.

Devon

 

ttt

 

I think 5V coil voltage (through a ballast resistor) is pretty reasonable. Remember, in
dynamic operation, there is zero coil current when the points first close, and zero V drop
across the ballast resistor, so the coil sees the full 14V or so. Only as the current builds
up (storing energy for the next spark) does voltage drop across the ballast resistor build
up. Eventually the maximum current levels out (at low or no rpm) at much reduced coil
voltage. If the coil voltage DID NOT reduce a lot, current would just keep increasing &
burn out the points, which the ballast is intended to prevent.

Some electronic ignitions don't need a ballast, because they turn on coil current JUST IN
TIME to reach desired maximum before spark, no current limiting needed. That is why,
it is necessary to find out if THIS electronic ignition operates that way. Bruce Roe

 

I called Mallory tech support yesterday and was told that i did in fact need the ballast resistor with the current setup I have but Bruce and Devon could you look at this thread I started about an engine stumble and let me know what you think maybe the two threads are related
Thanks
Chris

http://www.v8buick.com/showthread.php?240017-Engine-stumble-at-idle&highlight=