How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ron Your Own Question
Ron, ASE Certified Technician
Category: Mercury
Satisfied Customers: 35862
Experience:  ASE Certs and Ford Certs
Type Your Mercury Question Here...
Ron is online now
A new question is answered every 9 seconds

What can cause the #1 ignition coil to fail? I have replaced

Customer Question

what can cause the #1 ignition coil to fail? I have replaced the plug,pcm and crank position sensor and it still keeps failing.
Submitted: 2 years ago.
Category: Mercury
Expert:  Ron replied 2 years ago.

Hello and thank you for your question, The expert you had requested is not on line at the moment so I will help you with this, Sorry for the delay.

If you are sure the new PCM and coil is not defective the the next step would be to Ohm check the drive circuit wiring from the coil to the PCM to be sure its not shorted to ground. The drive circuit on the #1 coil is the lite green/white wire from the coil to Pin #26 at the PCM. Check this circuit to make sure its not shorted. See the wiring diagram for reference in the link below, copy and paste the link to your browser to open and view it.

Check this and post back if you have more questions and or need more help.

Customer: replied 2 years ago.
I tested the wire and there doesn't seem to be problem.
Expert:  Ron replied 2 years ago.

Well if you do not have a short to ground and or power in the circuit then I would suspect the new coil is just defective.