Problem Starting Engine

[stock333]

would the shifter handle effect the starting of the boat. Also is the neutral switch located in this unit.

Thanks

mark

[Phillbo]

Yes. If the handle is not in neutral the motor will not even turn over.

[mmwjr]

yes the neutral safety switch is located in the throttle control. The gear shift either needs to be in neutral or the shift mechanism disengaged by pressing in on the button before advancing the throttle.

[stock333]

Can some please tell me in mercruiser 5.0 where the neutral safety switch is located. On some ubtu tubes it shows in the stern of the boat that it is near the Cablevision the back of the boat and some say it's in the shifter
Thanks Mark

[mmwjr]

All Mercruiser I/Os have the neutral safety switch in the control at the helm. The only switch located on the engine is the shift interrupt switch for Alpha drive applications.

If you have 12Vs on the yellow/red wire of the slave soleniod when cranking the neutral safety switch is not the issue. However if you don’t have this voltage there is several things that could be the issue besides the switch.

[stock333]

When I turn the key to accessory the gauges normally start and the audio alarm goes on. Now when I turn the key there is no movement in the gouges or any audio alarm. When I turn to start nothing happens. The 2 battery's have 12.5 volts. the radio and trim tab and engine tilt all work but no movement on anything else. There is 12 volts going to the 50 amp circuit breaker a the motor. If I put a power probe on the hot leg of the key switch i also have 12 volts. If I turn the key to start with the power probe connected to the hot leg of the key the engine starts but when I remover it it shuts off.
Can the neutral safety switch have any thing to do with this? Or any other ideals

Thanks

[shrew]

I can't remember if the alarm sounds if the emergency shut off is off. I once had a similar issue starting the boat, the emergency shut off was set to on, but boat wouldn't start.

I toggle the emergency shut off to OFF, then back to ON. Then the boat started with no issues. It was like it worked the connection loose or there was corrosion that was knocked by cycling off and on again (Like unseating and reseating an ATC style blade fuse).

[mmwjr]

The neutral safety switch is only in the start circuit, if your gauges and alarm are not responding they are not getting power from the run “ignition position”. First see if you have 12V on the ignition switch “B” terminal. No power here check the 10 pin connector to see if it’s seated. If you have power on this terminal see if you get 12V on the “I” terminal when the key is in the run position.

[Phillbo]

Sounds like a bad ignition switch... If the kill switch was off the motor would turn over but not fire. The lack of gauges also sounds like a bad ignition switch.

[mmwjr]

Originally Posted by Phillbo

Sounds like a bad ignition switch... If the kill switch was off the motor would turn over but not fire. The lack of gauges also sounds like a bad ignition switch.

Maybe but first need to see if power is even getting to it.

[jparsons121]

Originally Posted by mmwjr

Maybe but first need to see if power is even getting to it.

Agreed. Power (and ground) flow from the engine harness thru to the helm and then back again for the start and run circuits