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Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3976
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
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I have a mid '70s OMC in a chevy block we have just replaced

Customer Question

I have a mid '70s OMC in a chevy block we have just replaced the head gaskets and upper seals. We put it back in the harness, turned the key and we have no power to anything, like dash lights and no start. I jump the starter directly and the engine started right up. The alternator then powered al the dash lights pumps and everything. What could I be looking for.
JA: Sometimes boat issues seem like they'll be really complicated, but end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Is there anything else important you think the Marine Mechanic should know?
Customer: Not at this time
Submitted: 2 months ago.
Category: Boat
Expert:  Charles replied 2 months ago.

Hello, my name is***** will assist you.

Expert:  Charles replied 2 months ago.

Check the wires on the back of the key switch. With the key off, the red wire should still show 12V between it and a ground. If it does not, there is an issue with the plug in on the engine or in the harness. If it does, turn the key to the on position and see if the ignition wire now has power as well. If it does not, replace the key switch.

To get more detailed, I will need the model number from the engine.