2005 263 - Engine Does Not Crank With Ignition Key

[Avg_Guy]

Question for 263 owners and those knowledgeable with 263s.

End of February, I picked up my 2005 263 with 496 Mag/Bravo 3 in Michigan and drove 2700 miles back to San Francisco area. Boat ran in Michigan but will not start since arriving home. As stated in subject, turning key switch to START does not initiate the starter. Batteries are fully charged, everything powers up when switched to ON...tried starting with Battery #1, #2 and both selected. Online research provided many potential causes including:

1. 50A engine circuit breaker tripped (checked)
2. 90A starter fuse blown (had a spare, ohm checked good, replaced with no change. Old fuse ohm checked, also good)
3. Neutral safety switch out of adjustment or ball detent stuck/missing (turned key to START, slowly moved control back & forth thru the neutral position with no change)

4. Ignition key switch, mechanical failure
5. Ignition key switch, loose connection
6. Wiring harness/ground wiring, loose or high resistance connection
7. Starter failure (motor/brushes, etc)
8. Starter solenoid (the solenoid mounted on starter)
9. STARTER SLAVE SOLENOID RELAY (the solenoid "typically" mounted near 50A circuit breaker)

My MerCruiser #30 service manual is a year 2000 publication and, obviously, does not address neither the 2005 model year, nor any specific boat manufacturer. Based on Youtube videos that I found on the subject, I worked through what I thought were the easiest (and what I could address with the spare 90A fuse) and I eliminated the 50A circuit breaker, 90A fuse (15 minutes, figured why not), and started troubleshooting #3 - neutral safety switch, as indicated above. I have a good multi-meter (Fluke 117) and reasonable skills, and will continue my troubleshooting, but need some assistance from "those in the know."

During my visual inspection to identify location of the listed components, I crawled all over the engine/engine bay, and I could not find #9 - starter slave solenoid (reference photos attached). I've seen Mercury Quicksilver identifying it as "starter/tilt trim solenoid relay," part number 89-96158T.

MY QUESTION: Does the 263 have this component and, if so, where exactly is it located?

VIDEO >> https://www.youtube.com/watch?v=FV20zDi1lNk

[jhnmdahl]

Do you have anything that looks like #5 in this picture (near the ECU)?

https://www.mercruiserparts.com/bam/sub ... 6/11746/30

If not, perhaps post a picture of your engine (with the top cover taken off) and someone's bound to know.

[capn272]

Is it not attached to the starter? It should be somewhere nearby given the amount of current that it allows to flow to the starter.

[bruceb58]

Is it not attached to the starter? It should be somewhere nearby given the amount of current that it allows to flow to the starter.

The relay they are talking about does not carry current to the starter...only the starter solenoid.

[bruceb58]

To the OP...what is the serial number of your engine?

[Avg_Guy]

Do you have anything that looks like #5 in this picture (near the ECU)?

https://www.mercruiserparts.com/bam/sub ... 6/11746/30

If not, perhaps post a picture of your engine (with the top cover taken off) and someone's bound to know.

Yes, that appears to be mine...and, yes, I need to setup an image hosting account.

https://photos.app.goo.gl/zX5vs32sq9yMLTuL9

[Avg_Guy]

To the OP...what is the serial number of your engine?

Bruce, was hoping that you would chime in. Serial number is 0W060217

[Avg_Guy]

Is it not attached to the starter? It should be somewhere nearby given the amount of current that it allows to flow to the starter.

Yes, as Bruce said, on some engines (but apparently not mine) the starter slave solenoid is an intermediate solenoid upstream from the starter solenoid that is mounted on the starter.

[bruceb58]

To the OP...what is the serial number of your engine?

Bruce, was hoping that you would chime in. Serial number is 0W060217

Did some initial looking and see that plate that jhnmdahl posted is basically the same for your serial number group. The relays on there indicate they are for the electrical shift.

I wish I had an electrical diagram for your motor. I am going to search for one. I will get back if I find something more.

Your 2000 manual likely doesn't cover the 496 since that motor didn't arrive until 2001 at the earliest. I know the 7.4L motors has the starter slave solenoid but am uncertain if the 8.1/496 has one.

[bruceb58]

So...I located the #30 manual and it is a Sep 2000 and should apply to your engine. It doesn't state anything about a starter slave solenoid. I wonder if it's the same as yours. Unfortunately, no schematics in the manual. You can PM me with your email address and I can send to you.

I think it's going to come down to getting your multimeter out and checking voltages starting at the starter solenoid and working your way backwards or at the ignition switch and working your way from there.

[Avg_Guy]

To the OP...what is the serial number of your engine?

Bruce, was hoping that you would chime in. Serial number is 0W060217

Did some initial looking and see that plate that jhnmdahl posted is basically the same for your serial number group. The relays on there indicate they are for the electrical shift.

I wish I had an electrical diagram for your motor. I am going to search for one. I will get back if I find something more.

Your 2000 manual likely doesn't cover the 496 since that motor didn't arrive until 2001 at the earliest. I know the 7.4L motors has the starter slave solenoid but am uncertain if the 8.1/496 has one.

I appreciate your assist...I will search online as well.

Mercury must have had some early 496 releases (maybe mid-year sales of new model year?) Manual #30 is specific to the 496 Mag (HO) engines, but wishing that I had thought about evolution of the electronics when I bought it (secondhand, ebay) as I now see that the Sept 2000 data won't cover all my concerns. It will help for now but definitely will search out another of the correct year.

[bruceb58]

I was also able to locate a #36 manual. It talks about a starter slave solenoid on certain models. You may want to look at this one...again, I can email it to you.

This manual is 2006

You have Multi port fuel injection right?

What voltages have you checked with a multimeter so far?

[Avg_Guy]

I was also able to locate a #36 manual. It talks about a starter slave solenoid on certain models. You may want to look at this one...again, I can email it to you.

This manual is 2006

You have Multi port fuel injection right?

What voltages have you checked with a multimeter so far?

Yes, mine is the multi-port FI. Honestly, I have only just started the troubleshooting, trying to familiarize myself with the components and their respective locations. I figured that I would begin at the ignition switch and work my way back to the engine bay checking the wiring connections along the way.

[Kate]

No "click," at all?

Some issues to consider: The 496 does not like corroded terminals or cables or batteries that are not fully charged.

The key to your mystery might be this: "drove 2700 miles"

That's a lot of shock and vibration, which can cause a loose connection somewhere. Check, for example, if the kill switch is grounded out.

[Avg_Guy]

No "click," at all?

Some issues to consider: The 496 does not like corroded terminals or cables or batteries that are not fully charged.

The key to your mystery might be this: "drove 2700 miles"

That's a lot of shock and vibration, which can cause a loose connection somewhere. Check, for example, if the kill switch is grounded out.

Agreed, which is why I included the long haul (over some less than stellar roadway) in my initial post...a loose ground or termination could definitely be the cause and finding it could be a long, tedious process. Sure hope that it is a component, but prepared to shake out wiring if required.