Key switch / Ignition issue

[Jpendef993]

1994 Searay 170 bowrider with 3.0 mercruiser.
I had a rusted / broken terminal on my starter, so I replaced it along with new solenoid. When I jump the solenoid, starter spins right up, so no issues there. I have power at the 50A breaker.
Outdrive trim works, as well as radio, fuel gauge, volt gauge, blower and horn.

I have no power at the keyswitch, so I replaced that as well. Still no power at all. Jumping the wires at the switch does nothing also. At this point I'm beyond my abilities.

Any help is greatly appreciated!

 

[alldodge]

Power goes to the key switch on the red/purple wire, which also has a 20 fuse. The fuse is probably a inline type. It will be behind the helm. Follow the wire to find it

 

[Jpendef993]

Power goes to the key switch on the red/purple wire, which also has a 20 fuse. The fuse is probably a inline type. It will be behind the helm. Follow the wire to find it

Thanks - ill check and report back

 

[Jpendef993]

Thanks - ill check and report back

Found the wire - no fuse. But I think I might have stumbled on the problem. My shifter goes in Forward & Reverse without pulling up on the release button. In other words, it won't go into neutral. That would cause my issues, right?

 

[Chris1956]

I faulty neutral interlock switch could cause your issue.

However, some MerCruisers have a slave solenoid that is activated by the ign switch. This solenoid then activates the starter solenoid. If the slave solenoid is bad, the starter solenoid will not activate under influence of the keyswitch. They are usually on the block. You might look for it in a wiring diagram.

 

[Jpendef993]

Thanks for the input! Ill let you know it turns out

 

[alldodge]

That would cause my issues, right?

Turn the key to start and hold, then pull the shifter back n forth a bit to see if it will start to crank. If it does its the neutral switch

If it doesn't connect voltmeter probe to Yellow/Red wire on the key switch and turn to start, should see 12V. If 12V is found then put probe on the small yellow/red wire located on the bottom of the slave solenoid

 

[Jpendef993]

Turn the key to start and hold, then pull the shifter back n forth a bit to see if it will start to crank. If it does its the neutral switch

If it doesn't connect voltmeter probe to Yellow/Red wire on the key switch and turn to start, should see 12V. If 12V is found then put probe on the small yellow/red wire located on the bottom of the slave solenoid

1st I need to check if it's in gear - ill try to spin the prop

 

[Jpendef993]

I faulty neutral interlock switch could cause your issue.

However, some MerCruisers have a slave solenoid that is activated by the ign switch. This solenoid then activates the starter solenoid. If the slave solenoid is bad, the starter solenoid will not activate under influence of the keyswitch. They are usually on the block. You might look for it in a wiring diagram.

I replaced that and checked it - power good and when I jumping, starter fires up the engine

 

[Chris1956]

If you have the slave solenoid, you can jumper it and see if the starter turns. You will want to find the battery power on the secondary winding, and connect that to the primary post that would receive power from the ignition switch.

Jumpering across the slave solenoid secondary winding proves nothing, as you have already determined that your starter solenoid is good.

 

[Jpendef993]

If you have the slave solenoid, you can jumper it and see if the starter turns. You will want to find the battery power on the secondary winding, and connect that to the primary post that would receive power from the ignition switch.

Jumpering across the slave solenoid secondary winding proves nothing, as you have already determined that your starter solenoid is good.

I will give that a try. My prop spins, so it's not locked in gear. I'm about out of ideas, so all suggestions are welcome

 

[Jpendef993]

I will give that a try. My prop spins, so it's not locked in gear. I'm about out of ideas, so all suggestions are welcome

No power on the yellow/red wire to the starter. Do you know if that line has a fuse? Looks like it runs into a group of wires behind the engine, then heads up toward the shifter

 

[alldodge]

There is no fuse on the wire and the neutral safety switch is inside the throttle control.

Look for 12V on the Yel/Red wire at the key when turned to start

 

[Jpendef993]

There is no fuse on the wire and the neutral safety switch is inside the throttle control.

Look for 12V on the Yel/Red wire at the key when turned to start

View attachment 329430

Understood - ill check tomorrow - thanks for the help

 

[Jpendef993]

The yellow /red wire had the issue, which I determined after checking everything with a volt & ohm meter. I replaced the wire and the switch cranked the engine up. Thanks for all the help!!!!!