mercruiser ign modules

[Wicked Performance Boats]

How do you test merc ign modules for spark? Test lite lites at coil neg, but doesnot pulsate when cranking. Budlight :confused:

[Wicked Performance Boats]

I can't believe nobody knows how to troubleshoot a mercruiser thunderbolt ign system! Budlight

[502 JET]

Is the ignition a Thunder bolt IV?If so I can help.

[Wicked Performance Boats]

It's a thunderbolt V. BL

[502 JET]

The book I have is for the IV system.If you cant find out any info get a Seloc manual that covers your model year it will have step by step instructions on trouble shooting the ignition system.