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1995 Ford Thunderbird Question: no fire from coil pack

 

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jdean, 4.6L V8, Morristown, TN, May 08, 2009, 06:06
 Rookie

my 95 ford thunderbird was missing thought it was bad gas, wasn't. Thought it was plug wires, wasn't. Thought it was the coil pack ( because im not getting fire out of two of the four plug wire connections) but it wasn't. What else should I do? Also my engine light is on, but it's missing so bad it doesn't drive well enough to take and have codes read. Is there something I can check myself? PLEASE HELP

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  • Answer #1

    irvtech May 09, 2009, 00:00
     Journeyman

    If you have no spark from two of the four towers of your coil pack, you need to check the wiring between the coil pack and the ignition module. Since you have spark at two towers, that proves you have power to the coil pack. Both sets of coil windings in the coil pack are fed by the same B+ feed,(red and light green wires to both coil packs too). The control side wires from the ignition module to the coil packs are tan/light green and tan/light blue for one coil pack. The wires are tan/white and tan/orange for the other coil pack. These wires and ignition module provide the ground for the coil pack and when this ground is interrupted that is when spark is delivered. If you want to check this yourself, I will try to guide you through it but , I have to assume you have some ability to work on cars and some understanding of basic electrical functions. On the offending coil pack we are going to test it the fastest way I know how. First you need a 12 volt test light, you will connect the clip end to the battery positive terminal. Test the light operation by touching the probe end to the negative terminal of the battery and verify that the test light works, once that is done, you remove the connector from the coil pack that has spark at two towers of the coil pack. You will need an assistant for this last part, You are now going to touch the one of the terminals at that connector that has one of the tan/+ (+ denotes the other color for the wire)wires, while holding the probe there(the clip end is still connected to the battery positive terminal) now have your assistant start the vehicle for about 10 seconds. If the ignition module and wring are good the light should flash while the motor is running. Retest the other tan/+ wire at the same connector in the same way. If the light flashes at both wires, you either have a bad coil pack or high voltage drop in the B+ wire to the coil pack or high resistance in the wires from the coil pack to the ignition module. I assume that you switched coil packs from one side to the other to determine that the coil pack was good. Good luck.

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