Re: Tr ignition desperation!!!
Leve is correct regarding the voltage. To get an accurate reading you really need a true RMS meter or use and Oscope. The voltge to the coil is a pulsing voltage...or in reality a pulsing ground...kinda.......the output of the module to the coil is anctual a solid state transistor that shorts to ground (almost) and causes the pulse in the coil. Remember, you have a positive voltage in one side of the coil, and the module shorts out the other side with pulses from the transistor (most likely and PNP). You can simulate the same thing by just connecting a ground to the neg side of the coil and then removing it. When you remove it, the coil will spark.
Now that we have that out of the way...the transistor in the module can only handle so much current. If the voltage drop across the coil is not enough, the transistor has to drop the voltage, hence it gets too hot. With the ignition on but the engine NOT running, measure the voltage on the pos side of the coil and compare it to your good jeep. I bet you need a resistor between the bat and the pos side of the coil. To be sure of the voltage drop, disconect the ign module and short the neg side of the coil....then measure the voltage on the pos side. On your good jeep, I bet it will be less then the bad one.
One the older GM cars (I bet Leve will remember this), you had 2 wires going to your coil. One was through a resistor that droped the voltage to about 8 volts, the other went to the starter solenoid. When you were starting your engine, the voltage from the starter sol was a full 12 volts, this gave you more spark for starting...once you backed off the key to the normal ign position, then you only had 8 volts going to the coil...thus the voltage was spark was smaller but your points (yes, points) lasted a lot longer. An old racing trick was to run a wire from the bat to a switch and then to the coil. When you had a race (and of course, I never raced on the street) you flipped the switch for a little extra power. Made a difference on high compression engines.
Let us know what you find.
84CJ7, 3"lift, 32"BFG, 4.10's, ARB Rear, Detroit Front, Solid Axle's, Durabak, York Air
They say we learn by our mistakes......I guess thats why we are all so smart.