Mercruiser 4.3L Engine Won't Start

[MikeEller]

Went out this morning. When I turned the key...nothing. No clicking, nothing. The dash gauges did activate and there is power to everything else. This is a 2006 Tahoe Fish and Ski Q6 with a Mercruiser 4.3L V6. I jumped the key switch to test that...nothing. I also cycled the throttle and emergency switch to make sure they were in the proper positions.
Any ideas?

 

[Bondo]

Ayuh,..... Welcome Aboard,..... Dead battery,..??

Less than 12v will power the dash, but not start the motor,.....

 

[alldodge]

What is the motor serial number?

Check for 12V at the coil
If 12V is present check the slave relay

 

[MikeEller]

Serial Number is OW343328
Gotta dig out the old multimeter....my son just took my good one to college with him
where do I find the slave relay?

 

[alldodge]

Thanks for the number
The slave is on top the motor and looks like the pic below. With the key on or off (doesn't matter) jump across the two large top terminals. When doing this it should energize the starter, then its probably the relay.

To verify if it does, then check to see if your getting power when the key is turned and held to "start" on the small lower yellow/Red wire. Not the larger one on top

 

[MikeEller]

Checked the slave relay. When I jumped the two large terminals, the starter did engage.

 

[MikeEller]

I do not have a second set of hands to check the small wires when key is turned....

 

[alldodge]

There is a high probability that the slave has gone bad.

Jump from the larger terminal with the Red/Purple wire to the small wire on the lower terminals with the Yellow/Red wire (remove the small yellow/red wire before jumping). If it does not engage then its the slave

 

[MikeEller]

OK...go from the large red/purple terminal to the yellow/red wire...correct....not the small terminal?

 

[alldodge]

OK...go from the large red/purple terminal to the yellow/red wire...correct....not the small terminal?

NO

Go from the large red/purple to the small yellow/red

Do remove the wire from the small yellow/red terminal to make it easier to jump and also not to back feed anything

There is a small yellow/red on the bottom terminal and also a larger yellow/red on the top terminals, you want to small one on the bottom

 

[alldodge]

Don't know which order the wires are in on your relay

 

[MikeEller]

The starer did energize when I jumped the large red/purple to the small yellow/red

 

[MikeEller]

So in the scenario, turning the key does nothing...no clicking at all. And doing the tests just completed indicates that the slave relay is bad?
Is that correct?

 

[Bondo]

So in the scenario, turning the key does nothing...no clicking at all. And doing the tests just completed indicates that the slave relay is bad?
Is that correct?

Ayuh,..... What you haven't tested is whether the key switch is puttin' voltage to the yellow/ red wire in the 1st place,.....

 

[MikeEller]

OK. Is there a test for the key switch? Or was that the test on the coil?

 

[alldodge]

The starer did energize when I jumped the large red/purple to the small yellow/red

Your relay is good,
Turn key to start and hold, then move the shifter a bit forward/reverse, but do not move it far enough to take it out of neutral. Trying to find out if its the neutral safety switch or not

A voltmeter could eliminate many of these things

If that doesn't cause it to crank, then need a long jumper wire and go from the Start terminal on the key, to the small terminal on the slave relay with the small yellow/red. Attach and try the key

 

[MikeEller]

I did jump the key switch too. That did not energize the starter.

 

[alldodge]

I did jump the key switch too. That did not energize the starter.

That's not what I'm asking, you do really need a voltmeter but............without one.............

The Yellow/Red from the key goes thru the neutral safety switch in the throttle handle, then it goes to the small yellow/red on the slave relay

We know the relay works because of jumping from the large red/purple to the small yellow/red

The dash gauges did activate and there is power to everything else.

You moved the shifter while hold the key to start and it did nothing.
The gauges are lighting up so the kill switch is not the issue

What we don't know is
Is the key passing power to the Yellow/Red (because no voltmeter)
Is power making it to the small yellow/red on the slave relay (because no voltmeter)

Run a long jumper from the Red/Purple terminal on the KEY SWITCH to the yellow/red small terminal of the slave relay

If it cranks, then there is power at the key switch

Move the long jumper from the red/purple to the Yellow/red terminal on the key switch, to the yellow/red on the slave relay and see if it cranks

If it cranks it a bad wire, connection or neutral safety switch
If it does NOT crank, then its a bad key switch

 

[MikeEller]

OK.
I really appreciate your patience...
Shifter test - engine did not crank
long wire from key switch to slave relay - engine cranked on both tests

 

[Howard Sterndrive]

bad neutral start switch in your shifter?