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Mercruiser 454 will turn over but will not start

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Didn't see your last post
ok you have a orange wire instead of red/pur

Is there 12V on the orange wire?

Yes, I do believe there should be 2 wires on the kill switch but right now the problem is you have no power on the purple, which means the "KEY" is not transferring power to it. Look on bottom of key, Org will be on B, Pur will be on I, and yel/red will be on S terminal
 
AllDodge said:
Didn't see your last post
ok you have a orange wire instead of red/pur

Is there 12V on the orange wire?

Yes, I do believe there should be 2 wires on the kill switch but right now the problem is you have no power on the purple, which means the "KEY" is not transferring power to it. Look on bottom of key, Org will be on B, Pur will be on I, and yel/red will be on S terminal
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Yes, 12V on the orange from the fuze. Plus the engine still cranks. Just no spark / dash power.
 
I think there is a loss of info as the posts grow.

Please reply stating exactly which terminals on the KEY switch have what and when

So with key off, only wire is large red or orange should have 12 volts and this will or should be true always no matter what the key position is..

with key in run position only, There should be 12 volts on Purple wire. Purple is Ignition On and feeds all gauges and engine with power for ignition BUT goes thru the Lanyard switch. Can you follow purple wire on ignition switch to see where it goes?

According to schematic it should be going thru Lanyard switch then up to gauge cluster and onto engine TWO wires One in and one out.

I highly doubt the lanyard is a single wire connection as it is a SWITCH and when the lanyard wire is removed the switch opens and NO power to gauges or engine.
That wire going to alarm, Should that actually ALSO be plugged into the Lanyard switch? not sure where the other end of that connection is going or coming from.

The yellow/red should only have voltage when in the cranking position. the Purple wire will also have power at the same time as this supplies voltage to ignition as mentioned above.
 
can you follow purple wire on ignition switch to see where it goes?
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Like you mentioned and in the pic, it goes to the kill switch. Then that goes nowhere... What is a little bizzare is that, unless somehow things became unplugged and are now missing- the dash was working prior to the clicking after turning the key at the boat ramp. Had no control on any electronics, even trim. I swapped batteries (thinking they were dead) and same problem. Heard clicking near where the coil was, so i unplugged it and plugged it back in. Engine now cranks, but no power to dash / coil.

I will go mess with the meter again and report my findings. If you want more pics, just let me know.
 
Are you referring to Relays that you unplugged and plugged back in? Or are you referring to a solenoid? According to schematic, the only plug is at TB module. purple connection to coil should be ring terminal
 
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Peckadelic said:
That purple wire goes up to the buzzer behind the dash. It is zip tied for some reason to the rest of the ignition.

Should there be 2 terminals to the kill switch? Also how would that kill the dash power?
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One problem when testing for good connections with a volt meter is, A weak connection can show 12 volts. If you were using test light it would show a dim light if connection was weak. Bright light when connection is good. Just an FYI for the future. Any auto store will have then for under $20.
 
Thanks to both of you guys.

The culprit was correctly pointed out. The wire leading to the buzzer..? I put it on the kill switch and wired the buzzer to one of the gauges.

We are back working. My question is.. how the hell did it ever run with this wiring configuration? I am almost suspect of my mechanic. Disappointing as my summer has been plagued with issues on a really nice boat.
 
I bet the female spade connection circled in yellow was plugged into lanyard and simply fell off and when you removed dash section, the buzzer wire pulled back as the buzzer wire Is short.
 
You made the right decision by attaching buzzer to a down stream purple connectiin. It should not have been attached to lanyard unless done with the right length of wire and correct multi male spade at lanyard.
 
kghost said:
You made the right decision by attaching buzzer to a down stream purple connectiin. It should not have been attached to lanyard unless done with the right length of wire and correct multi male spade at lanyard.
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From what it looks like, that connection would never have fit on the kill switch. No clue what was going on there.

Thanks for the knowledge sharing- hopefully this thread helps someone else in the future.
 
Peckadelic said:
That purple wire goes up to the buzzer behind the dash. It is zip tied for some reason to the rest of the ignition.

Should there be 2 terminals to the kill switch? Also how would that kill the dash power?
Click to expand...
A kill; switch is installed in the wire going from the ignition switch to the gauges and ingnition system- if you didn't have one and you cut the wire while it was running, what would happen? This is called a 'series connection'. Look in the area behind the panel with the igniotion and kill switches for a loose purple wire and connect it to the kill switch.

The gauges need 12V to operate- if they lose that 12V, they won't react to the key being turned to ON.
 
I didn't jump in, but the whole wiring is sus due to the Homer Handyman crimp terminals. This is not the way the boat was born, so the wiring could be wrong in more than just this one place. I think you need a manual with wiring diagram, a test lamp, and some quality time just you and the wiring to figure out whether it's all done right or what. The thing to be most concerned with is loose connections. Proper crimps won't let the wire fall off. Invest in a good crimp tool and order some adhesive lined shrink tube crimp terminals from Amazon.
 
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