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Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 10898
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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89 four Winnsboro cobra 350 5.7. Starts when cold after its

Customer Question

89 four Winnsboro cobra 350 5.7. Starts when cold after its warm sometimes it won't start check for voltage at coil using test light no light so if I jump it from the hour clock lead it starts replaced ign switch same result added a push button for starter still have same problem
Submitted: 1 year ago.
Category: Boat
Expert:  Tan replied 1 year ago.

Hello. My name is Tan.

Have you checked for voltage on the red/purple wire at the key switch when engine dies?

Customer: replied 1 year ago.
engine doesn't die I shut it off and yes have power didn't use vom
Expert:  Tan replied 1 year ago.

Sorry I meant do you have voltage on the red/purple at the key switch when you try to restart?

If you can jump to the key switch from another volt source this tells me you have lost voltage to the key switch?

Have you inspected the 50 amp fuse at the motor for corrosion?

Customer: replied 1 year ago.
I will check it now n be right back
Expert:  Tan replied 1 year ago.

Ok the voltage to the key switch runs from the starter batt connection to the slave solenoid then to the key switch. So somewhere between the batt cable connection and key switch you are loosing voltage.

Customer: replied 1 year ago.
checked connections nothing found how ever I checked voltage at key switch and found i have 12 v at batt post on switch when i turn key to on it drops to 10v at coil it drops to4 v
Expert:  Tan replied 1 year ago.

Ok you have a bad connection on the red wire or a bad wire. Check the fuse at the engine for corrosion. Remove each connection where the red wire connects clean with wire brush.

Here is a wiring diagram follow the red/purple from the starter battery cab;e connection to the key switch. Somewhere between the batt cable connection and the key switch is a bad connection or damaged wire. The plug where the boat harness connects to the engine harness is a place of concern the pins can be come corroded and even break.

Post back with questions and findings.

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