After cooling it runs normal. If 12 volts is present remove the coil spark wire from the distributor and connect it to a spark gap tester to ground.

Tz 8352 Omc 3 0 Wiring Diagram Mercruiser 165 Ignition
Thunderbolt iv wiring diagram. Thunderbolt iv and v ignition systems. See application fits and newer mcmmie l l l l mpi engines with ecm fits gm v 6 engines with thunderbolt iv v hei ignition. Lead to the whitered wire terminal at the dist. Whtgrn from module to dis. When hot the ignition fails completely. Aug 07 thunderbolt iv mounted on exhaust elbow whtred from module to dis.
4b ignition system wiring diagram. Since we get questions about these systems i though i could relate my findings ala caotharvôçª there is a reason i researched this. It shows the components of the circuit as simplified shapes and the capacity and signal connections between the devices. Thunderbolt iv ignition wiring diagram wiring diagram is a simplified standard pictorial representation of an electrical circuit. V6 mercruiser engine thunderbolt iv ignition and forgot how all the wires i have the full seloc manual so i already have these wiring diagram that you. Lead to the engine ground and pos.
Connect your voltmeter neg. Thunderbolt v ignition wo knock sensor. Remove the whitegreen lead from the dist. Wignition key on and bilge well ventilated of gas fumes. The thunderbolt v has 5 wires two of which go to the distributor one is a wiring diagram. Second generation thunderbolt iv ignition control module this module is mounted on a triangular plate and requires the use of adapter harness 15275a1.
Identifying the type of thunderbolt iv module original thunderbolt iv icm this module is mounted on the exhaust elbow and has an aluminum housing. Fits gm v 6 engines with thunderbolt iv v hei ignition. Wiring diagrams 4f 3 thunderbolt iv with ignition module mounted on. My 2452 with a 57l 250 hp 2 bbl carb engine had developed a problem. Jun 19 need wiring schematic for mercruiser. Adapter harness 15275a1 is no longer available from the manufacturer.
It should read 12 volts. Tests for tb ignition. 4b mcm v 6 cid l with thunderbolt iv on your mercruiser are designed and manufac tured to l lx. L grounding the purple wire does not disable the electronic advance like answered by a verified marine mechanic we use cookies to give you the best possible experience on our website. Wanted to replace the mercruiser ignition system with something new.