dwaynew

Hi all. I'm new to the forums so bare with me. I have an issue on my 68 GTX. 440 with upgraded electronic ignition. My ignition module failed so I replaced it with a brand new mopar orange box and when it started everything seemed OK until about 2000 rpm. Then it was almost like there was a rev limiter and a miss. I then took this box off and installed a mopar chrome box from another car and everything seems good. Any thoughts on why this is happening.? I am ok running a chrome box but not sure why the orange box will not work.

Dwayne

Barfly

I know there is a difference in the ohm rating of the ballast resistor depending on which box you use..... I'll try to find the info....

Okay, here is the link where I saw the reference to the two different resistor ratings

about mid page they advertise

BALLAST RESISTORS
P2444641 1/4 ohm for chrome box and 4876733 coil 13.00
P5206436 1 ohm for orange box and 4876732 coil 8.50

dwaynew

Thanks for the info I will try this and see if this fixes her up. I am still confused though why the orange and chrome boxes would work on one car but not the other?? One is a stiock 440 and the other is a stroked 440??

dwayne

Archer

dwayne -

Barfly may be right about the resistor match, but a defective box is always a possibility.

If you want to find out for sure replace the orange box AND the resistor from the other car.

Archer

67 GTX

exactly the same thing happened to me
i found out from mopar that the orange box's that they are selling have had some durability issues
also, my problem turned out to be a mis-wired harness

dwaynew

Thanks all for the ideas so far. I did discover that the ballast resistor from Napa is about 3 ohms where the mopar ones are either .25 or 1 ohm, any idea if this will make any difference??

Dwaynew

67 GTX

i think it might
the ballast resistor must be matched to the box

rdrunner1974

The higher the resistance, the weaker the spark. Think of it like a dimmer switch, the more resistance you apply, the dimmer the light.