Mercruiser 4.3L Engine Won't Start

[Bondo]

What we don't know is
Is the key passing power to the Yellow/Red (because no voltmeter)
Is power making it to the small yellow/red on the slave relay (because no voltmeter)

Ayuh,..... Even a test light would help,..... Alot,.....

 

[alldodge]

bad neutral start switch in your shifter?

Agree, most likely and number one guess
Can also be bad connection/corrosion at neutral safety, 10 pin engine connector, at slave terminal connection or key switch terminal connection

 

[MikeEller]

I have cleaned the connections at the slave relay and the key switch. Haven't dug into the neutral switch yet.
can you run me through the volt meter tests...so if/when I find it I can do that testing as well?

 

[alldodge]

Key switch
Main power comes in on Red/Purple wire
Key ON will be 12V on Purple wire
Key start will be 12V on Yellow/Red wire (goes thru Neutral safety to slave)

 

[alldodge]

A visual

 

[MikeEller]

OK. I am going to pick up a meter tomorrow. Will resume troubleshooting tomorrow evening.
I appreciate all the assistance!

 

[MikeEller]

OK. Back at it.
I hit the key switch with the multimeter. Key On purple wire = 12.44V. Key Start yellow/red wire = 12.33V
So the voltage looks good coming out of the key switch...to me anyway.

 

[alldodge]

Looks good so far

 

[MikeEller]

What's next?
Is there a way to test the neutral switch directly?

 

[MikeEller]

OK. Found the problem.
I started looking hard at the throttle housing where the neutral relay is. The yellow/red wire goes in and then comes back out and continues to the slave. The wire sets are not continuous. I guess they are plugged into the wires for the switch. One of those wires was broken away from the connector. So no way for power to get to the slave relay.
It was tucked up there pretty good...hard to see.

 

[MikeEller]

Will run a new wire and connectors. Do you know off hand what gauge that wire is? 14 or 16?

 

[alldodge]

Cool, always satisfying to find the issue your self

 

[MikeEller]

I really appreciate your time and effort.
Obviously I am new at boating. And I learned a lot from you.
And don't go too far...I am sure I will be back again!
Again Thanks.