I have #3 coil that keeps burning out, trying to check the wires unplugged from the coil. With the test light I got voltage on the red wire. How do you check the blue wire?

 

IIRC the ECU/PCM sends a signal to one wire to get voltage while the other one is constatnt.. (seems an odd system to me but I'm not an electrical engineer.) so you need the truck running to test it. I think. Mine kept burning out coil #1 and I have yet to figure out why. Even changed the ECU/PCM (then I think my engine just blew up.. another post I rant about that.) Good luck.

 

Thanks, you are right it has to be running. I don't know what to do with my money pit. Sell it at a loss probably.

 

Hoping one of y'all figures it out. Here's a basic troubleshooting guide .

 

Yea that's where I'm at with mine. Going to get a really diagnosis and see if it's worth fixing at this point. I've got more into it then it's worth.

 

I've worked on a Ford and Hyundai in the past that had very similar symptoms.When I investigated it was caused by a mechanical condition that lead to the coils burning out.The ford had a intake coolant leak that migrated down the cyl head and filled up a spark plug well shorting the coil and setting off a CEL .The hyundai had a bad spark plug tube seal inside the valve cover that let motor oil fill up the tube with oil,shorting out the coil and setting off a CEL for a random misfire.Anyway,things you might want to look at.