Re: merc coil testing Home › Forum › Ask A Member › merc coil testing › Re: merc coil testing debeReplies: 103Topics: 0 June 7, 2018 at 8:16 pm #77614 I have a Mercotronic 9800 that has a CDI coil test function. This is the circuit of the CDI function of it. So yes there is one model that can be used to test CDI coils.