Troubleshooting starting

[saltydogjeff]

I have been trying to get my engine running. It starts when the stern drive is not connected. This makes me thing that the neutral safety switch in the controls is working properly. When the stern drive is connected, it will not start. This makes me thing it could be the neutral safety switch on the transom bracket.

I am going to try to short the one on the transom bracket. Any ideas to help troubleshoot?

Engine: 1988 470 Mercruiser
Drive: 1988 Alpha One
Can't find serial numbers on the alpha one, and I can't get to the motor right now.

 

[dubs283]

Re: Troubleshooting starting

there is no nuetral safety switch on the transom assy - only one in the remote control assy, it prevents the engine from turning over

the switch i think you refer to at the shift plate is the shift interrupt switch, just disconnect the wires and see if you get spark

chances are if the engine starts the problem is with the shift cable or adjustment

 

[saltydogjeff]

Re: Troubleshooting starting

So short the shift interrupt switch and see if the engine turns over? If it does it is cable related?

 

[dubs283]

Re: Troubleshooting starting

dont short the switch, just disconnect the wires

if the engine runs, yes the issue is either the switch, but most likely the cable or cable adjustment

 

[Bondo]

Re: Troubleshooting starting

So short the shift interrupt switch and see if the engine turns over? If it does it is cable related?

Ayuh,... Welcome Aboard,.... You've gotta talk the lingo used here,....

Is the problem the motor won't turn over,..??
Or is that it turns over, 'n Don't Start,..??

The Neutral safety switch will stop the motor from Turnin' over....

The Shift switch can stop the turnin' motor from Startin'....

So Which problem ya got,..?? Is it not Turnin' over, or not Startin',..??

 

[saltydogjeff]

Re: Troubleshooting starting

It's not turnin' over.

It used to turn over and start without the stern drive. Then with incorrect installation of the stern drive, it would not turn over. Then, when I removed the stern drive, it would not turn over.

This morning I disconnected the shift switch, and could not get it to turn over. I then shorted the shift switch (black to white) and couldn't get it to turn over. I then opened up the remote control and noticed that the neutral switch was not connected. The black was not connected to the neutral safety switch. I looked for the connection point but could not find where on the neutral safety switch it went. There was only 1 point for the white lead. I took a picture, and I had a picture from when I previously removed the neutral safety switch, and saw that it was just sort of stuck to the side with grease. Is this a dielectric grease that connects the circuit when the switch is made?

 

[saltydogjeff]

Re: Troubleshooting starting

 

[Bondo]

Re: Troubleshooting starting

Ayuh,.... Yer still All over the place,...

The Shift Switch, ONLY controls the Ignition Circuit....
It has Nothin' to do with the Starter circuit....

The Neutral Safety Switch, Sounds to be yer problem....

 

[saltydogjeff]

Re: Troubleshooting starting

Makes sense. So I am probably in the right place with the controls. From those pictures, do you know where the other lead is suppose to go?

 

[saltydogjeff]

Re: Troubleshooting starting

After looking at the spec I believe it is solder type. The connector is underneath.

 

[Bondo]

Re: Troubleshooting starting

Makes sense. So I am probably in the right place with the controls. From those pictures, do you know where the other lead is suppose to go?

Nope.... The Neutral safety switch is a pass-through switch, that should have 2 yellow/ red stripe wires...

In neutral, starter power passes through...

In gear, the circuit is broken...

 

[Don S]

Re: Troubleshooting starting

Look at the neutral safety switch wiring in this drawing. Just hook the wires (G and H) together to bypass the neutral safety switch in the throttle control for testing.

View attachment Troubleshooting a Mercruiser 470 Starting System.pdf

 

[saltydogjeff]

Re: Troubleshooting starting

I bypassed the neutral safety switch to get the motor to turn over. Now I see I have another problem with the motor starting. I will go read the faq about troubleshooting starting. When I tried starting it, I moved the throttle in and out of gear in an attempt to get the shift switch to work, if that is the issue.

 

[Don S]

Re: Troubleshooting starting

If you would get your mind off that shift interrupt switch for a while, you might get your engine running.
disconnect one of the wires from the shift interrupt switch, and leave it off for till you get the engine running.
Then, check to see if you have spark from the coil.
Remove the coil wire from the center of the coil tower and hold it about 3/8 to 1/2" from a clean ground and crank the engine. You should get a bright blue spark that snaps the gap. Yellow spark will not start an engine.
Do you use the throttle only button on your throttle shift control?

 

[saltydogjeff]

Re: Troubleshooting starting

I checked the spark from the ignition coil to ground. The spark did not seem to be the bright blue necessary for ignition. I am going to try replacing it understanding that the current one appears old, corroded, and not working properly. Where can I find the correct part for this 470?

 

[Don S]

Re: Troubleshooting starting

Crank the engine over and see what the voltage is on the + terminal of the coil while cranking (meter black wire on ground, red wire on the + terminal of coil)

 

[saltydogjeff]

Re: Troubleshooting starting

Replaced the ignition coil. Doing the same thing as previous. Have yet to check voltage. Video below.

 

[saltydogjeff]

Re: Troubleshooting starting

i took a reading from the + of the ignition coil to ground while cranking and got a reading of 10 volts

 

[Don S]

Re: Troubleshooting starting

Put in new points and condenser.

 

[saltydogjeff]

Re: Troubleshooting starting

What's that? Or Where can I find the part?