2005 4.3 liter Mercruiser ignition trouble

JustJason said:

Get a 12-14 gauge jumper wire with alligator clips and clip one end to the same terminal on the key switch, the other end to the positive terminal on the ignition coil. Just run the wire right across the boat. Bet it starts.

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I bet you are right but I don’t think that will tell me where the problem is. I now know I’m losing power somewhere between the switch and the coil. That kill switch seems awful suspect? Does anyone have info on how to get it out without wrecking it.

Not my boat but it looks very similar to this. Mine has a pad behind it that I guess is for your arm.

kepruno said:

I bet you are right but I don’t think that will tell me where the problem is. I now know I’m losing power somewhere between the switch and the coil. That kill switch seems awful suspect? Does anyone have info on how to get it out without wrecking it.

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Correctly I don't see how the kill switch is the problem because you said

kepruno said:

Every wire except the purple has or gets 12 volts when the key is turned to start. To further clarify, every single wire is disconnected except the power.

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The purple is not getting power so it's currently not the kill switch

alldodge said:

Correctly I don't see how the kill switch is the problem because you said

The purple is not getting power so it's currently not the kill switch

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That’s when I had my head up my ass and I was checking the wrong purple.
I should have said every connection except A gets power when the key is turned to start.

Currently have power at the switch (I), not at the coil.

kepruno said:

That’s when I had my head up my ass and I was checking the wrong purple.
I should have said every connection except A gets power when the key is turned to start.

Currently have power at the switch (I), not at the coil.

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I think you need to summarize what exactly has been done to troubleshoot, and what exactly the symptoms are/where. especially since you supplied wrong information...(what is "a"? accessory on the key switch? irrelevant if so)

nola mike said:

I think you need to summarize what exactly has been done to troubleshoot, and what exactly the symptoms are/where. especially since you supplied wrong information...(what is "a"? accessory on the key switch? irrelevant if so)

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Agree that ‘a’ is irrelevant. Now I know.
Summary:
1) followed trouble shooting flow chart to -replace distributor sensor - so I did. Cap/rotor and sensor all replaced.
2) low voltage at +terminal on coil while cranking. 12v with key on.
3) ‘I’ terminal at keyswitch has 12 volts while cranking - with all wires connected - new key switch is functioning properly (so was the old one) voltage at power supply to key never drops either.
4) I learned more about 12v systems in the last week than the past 46 years on this rock
5)Appears to me I’m losing power between the key and the coil. I’d like to look at the connections at the kill switch but I don’t know how to get it apart without wrecking it.

5)Appears to me I’m losing power between the key and the coil. I’d like to look at the connections at the kill switch but I don’t know how to get it apart without wrecking it.

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Ayuh,........ Is there ignition power(purple) at the big cannon plug, where the boat meets the motor, when the key is "On",..??

Rather that takin' a chance on breaking that switch, any chance you can see the wiring behind that panel,..??
There should be a red, a green, 'n blue wires for the trim,....
a yellow/red wire to the neutral safety switch, 'n back to the harness,....
'n of course the purple wire up to the kill switch, 'n back to the aft harness,....

kepruno said:

I should have said every connection except A gets power when the key is turned to start.

Currently have power at the switch (I), not at the coil.

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Move purple wire to I connection

alldodge said:

Move purple wire to I connection

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Wondering if someone’s been switching wires at the key switch as the colors seem off to me unless I’m going colorblind in my old age ha ha… the colors seems backwards between the I and A.