[cracing]

I will srart at the beginning, A friends son desroyed the ign. switc in his 89 F 150 with 351. We went to store where he had left it,jumped the magnetic sw., got under truck & put in drive to get to shop.When he wanted to shut it off he pulled the coil wire off dist cap. After replacing cyl & keys & broken parts in coluum the truck turns over but wont fire.No spark is present coming out of coil. Fire is at terminal of coil with switch on. No codes stored. Changed coil,no fire, Could the secondary voltage have reversed & burned out the ign. module on dist, or stator in dist, PCM or all of the above? All my manuals have test procedures using a breakout box & I dont have one. Any one have an idea or know of a GOOD manual that has a usable flow chart to troubleshoot this problem? Surly someone has experienced this before. Thanks.

 

[cracing]

Well all I can say is dont pull the coil wire with engine running. I have seen in many shop manuals not to even check cyl. balance by pulling one plug wire as it could damage electronics. Have seen it done & have used this method many, many years with no problems at all till now.The secondary voltage did follow the wire to Ign. module & burned it out. Replaced module today & engine fired up.