350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Hey guys,

So I have a starting isue I can't figure out on 2001 formula. I have 6 yr old twin 350 Mag Horizons that have always started up fine, no issues. I winterized them in the fall with no issues. It is now spring and my starboard side engine starts up fine but the port engine doesn't even give a buzz when I turn the ignition key. Listed below are the details.

No buzzer sound or guage movement when key is turned on port engine. I do get it on starboard engine
No clicking at the starter.
There are 12 volts at the back of both engine key switch
Jumping the terminal at the back of the key switch do no good; even with the key in the switch
I have swapped both swicthes with no luck
Batteries are installed, leads brushed clean and charged and the boat is hooked up to shore power
I have unplugged the main wire harness and see no corrosion and plugged it firmly back in
I have played and jiggled the kill switches for both engines. they also have no part to test on them. seem straight wired in
I have moved around the shifters and made sure they are in neutral, but they are hard to tel when in gear
I have taken a hammer to the starter solenoid ( extremely difficult to reach, forget about even seeing)

I have heard I should check the ignition module, neutral safety switch and the fuse in line from the key switch. I can't find either. The neutral swicth I can't get to. I have downloaded the manual.

Any suggestions without pulling this engine to get to the starter and neutral switch?

Thx

Brian


(2006) 350mag horizons (OW359452)
Bravo 3

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Does the starter turn the engine over? or is that what isn't happening.

If the starter isn't cranking, then this should help you find the problem.

View attachment 189649

See reply #22 for new file.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Did you check the main breaker on the top of the mortar? There is a little lever on the side that will pop down when tripped. I accidentally hit the test button on mine. No gauges buzzer crank over etc.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

twin engine should have 2 battery switches and the neg cables should all be hooked together.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Ok to answer a few questions and then ask some.

Don you are correct the engine does not cranck its as if its not even hooked up to a battery. On the troubleshooting diagram. Is the slave solenoid (the jklm) different from the solenoid mounted on top of the starter? If so where is it at? Also can I just use a multi meter instead of grounding to the battery? Lastly I will have to yank manifolds and risers off both engine or pull the engine to get access to starter so will check the rest first.

Agallant80 - Are you referring to the breaker on top of the motor? If so it is not popped out in comparison to the other engine. I tried pressing it in to see if it would pop out and then back in but I couldn't get it to do so. But I didn't notice any lever either. I also reset the breaker for that engine that is under the dash; no luck.

Bt- Doctur - I only have one battery switch, but the neg cables do hook up together I am fairly certain

Tmrw I will check the circuit breaker and look more for that fuse coming off the ignition. Just couldnt find it today

Thx guys

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

dolemite_1 said:

Lastly I will have to yank manifolds and risers off both engine or pull the engine to get access to starter so will check the rest first.

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Though this does not appear to be your problem you should know that there is a 90 amp fuse that mounts to the starter stud. The stud is the same stud that connects the main battery cable to the starter. One quick easy test to see if the 90 amp fuse is flowing power to the engine is to test for 12v at the orange wire (stud) on the back of the alternator. If there's no 12v at the orange wire, then there would be a problem at either the battery switch or between the battery and the starter or fuse.

Don has a good test to follow the starting system up in the forum stickies, here it is for you if needed, http://forums.iboats.com/mercruiser...ting-your-engines-starting-system-167035.html

dolemite_1 said:

Agallant80 - Are you referring to the breaker on top of the motor? If so it is not popped out in comparison to the other engine. I tried pressing it in to see if it would pop out and then back in but I couldn't get it to do so. But I didn't notice any lever either. I also reset the breaker for that engine that is under the dash; no luck.

Tmrw I will check the circuit breaker and look more for that fuse coming off the ignition. Just couldnt find it today.

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Agallant80's circuit breaker is a newer style breaker then what you have. Yours is a red 50 amp button to push and his has a yellow lever to throw.

Sometimes the red 50 amp button takes lots of effort to push for a reset.

dolemite_1 said:

No buzzer sound or guage movement when key is turned on port engine.

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Are you sure that your lanyard kill switch for that engine is not in the off position? sometimes they need a resting as well.

If you have no power to the gauges then it appears you have a problem with the ignition circuit which is controlled by the purple wire located at the (i) on the back of the ignition key. The lanyard kill switch is a break in the circuit that could go bad at times.
See Page 126 of 137 for a reference diagram,
http://www.boatfix.com/merc/Install/gas/86017211.pdf

Hope this help, good luck.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

So I will check for 12 volts on the back of the alternator since I have easy access to it. I also think i tracked down the location to the slave solenoid as being near the ecm on top of the motor.

Another question; concerning the red/ purple wire coming off the ignition switch that has the fuse inline (that i cant find) on its way to the main wiring harness. If i test for and find 12 volts at the 6 plug in the wiring harness that should tell me that the fuse in line to the ignition is bad correct? or can I just assume that the fuse is good considering I have power at the switch? does that make sense?

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Your ignition switch wiring depends on how the boat manufacturer wired it, so just follow the red/purple wire to where it plugs into the harness going to the engine, if there is a fuse, you will find it.

You also said in your original thread that you have power to the switch. How did you test this? Or did you just assume you had it, because if you have power to the switch, then you know the fuse you are looking for is ok, and you also know the circuit breaker on the engine is good. The kill switch has nothing to do with your cranking system, so that isn't a concern at this point.

You need to find the circuit breaker on your engine, and the slave solenoid. I show a picture of what the slave solenoid looks like, and it's the only one on the engine, and it has yellow/red striped wires on it. Look around your engine.
I looked back at some of your older threads, and you had an issue with salt water that may be part of the problems. But you have to do the voltage checks properly in order to find the problem.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Hi Don; Yes there is power to the switch. I tested it with a multimeter at the terminals on the back of the switch. It has the same reading as the working switch on the other engine. I even swapped switches. Glad to hear that power to this switch means the 90 Amp circuit breaker on the engine is good. I could not reset that thing. I will track down the salve solenoid today and test it.

Thx

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Not talking about the 90A fuse on the starter, was talking about the 50A circuit breaker on the engine (red arrow below) the solenoid is right next to the circuit breaker (solenoid is blue arrow)

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

How did you actually check for voltage on your ignition switch?

With a DVM (Digital Volt Meter) you need to have the black test lead on a a good ground, then your red test lead on the B terminal of your ignition switch. Is that how you did it? You DO NOT use both test leads on the switch.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

check your messages

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Bt Doctur said:

check your messages

Click to expand...

Does that mean the rest of us no longer need reply and you are taking personal control of the problem?

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

dolemite_1 said:

(2006) 350mag horizons (OW359452)

Click to expand...

Thanks for adding this important info today, Earlier today while laying out in the sun in newport beach ca, i started thinking what engine model did you have. Then i remembered that on this engine model next to the ECM area you should have a main power relay and some fuses that need to be checked out. Everything your describing could very well be one of these items are bad.

See item numbers 15, 16 & 17 in the link below for what to look for,
http://www.mercruiserparts.com/Show...cal+Components(Mechanical+Throttle+and+Shift)

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

No ,it means I`m tired of typing and maybe a phone call would resolve his issue and the result can be posted for the next person with a similiar proble.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Bt Doctur said:

No ,it means I`m tired of typing and maybe a phone call would resolve his issue and the result can be posted for the next person with a similiar proble.

Click to expand...

That is really rude behavior in a forum, but Ok, we will be waiting for what the cure was.

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Ok so here is the update with some progress. Sorry for the delay but work got in the way yesterday. First off thank you guys very much for the help; I greatly appreciate it.

I folowed the diagrams and checked some more connections. Below is what I found.

Tested the circuit breaker on both engines and both were fine.
I jumped J &K on the salve solenoid and cranked the engine (phew)
However on both engines jumping L &M did nothing, and I did not find power to M with the key on start and grounded to the battery even though the instructions said I should. This is on both the working and non working engine! (ODD)
Next at the helm ignition swicth I retested (thx Don) with the ground on the block under the dash. I had power when I touched the B terminal on both engine switchs.
Next I had 12v on the I terminal (purple wire going to gear shift) when the key was turned to start for the good engine. However I only had 1.2v when the key was turned to start on the bad engine.

The rain really started coming down at this point so I couldnt investigate further but the problem seems to be a short on the purple wire from the ignition switch to the gear shifter. With that being said, since I got the boat (1 1/2 yrs ago) my gear shifter never gave a solid indication when it moved between gears. Side note- the previous owners marina swicthed out the shift cables about 6 months before I bought the boat. I assume my issue is in the gear shift box which I have no experiece in working on.

So what do you guys think?

thx again

Brian

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Next at the helm ignition swicth I retested (thx Don) with the ground on the block under the dash. I had power when I touched the B terminal on both engine switchs.
Next I had 12v on the I terminal (purple wire going to gear shift) when the key was turned to start for the good engine. However I only had 1.2v when the key was turned to start on the bad engine.

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The purple wire has nothing to do with the the starter turning the engine. It's only for ignition. So even if you took the purple wires off of the ignition switch the engine should still crank.

Back to the slave solenoid. Nothing will happen when you jump L to M. You need to jump J to M and the engine should crank over.

Do you have more than one purple wire on the ignition switch?

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

Ok I did not try jumping j to m but will do so tmrw. I was going by the directions in the link above stating that it should crank when you jump L and M . There is only 1 purple wire on the bad ignition switch ignition but in the good ignition switch there is an additional black wire piggybacked on one of the terminals, pretty sure the yellow red line.



Thx for the heads up

Re: 350 Mag -Wont't start - No buzzer or guages working but has power to keyswitch

dolemite_1 said:

Ok I did not try jumping j to m but will do so tmrw. I was going by the directions in the link above stating that it should crank when you jump L and M . There is only 1 purple wire on the bad ignition switch ignition but in the good ignition switch there is an additional black wire piggybacked on one of the terminals, pretty sure the yellow red line.

Click to expand...

Might want to look at the instructions again, because I can't find it, and if it does I need to fix and replace the file. If you do find it, what step number is it in.

Not sure why you have a black wire on the good engine. Something funny there.

Disconnect the purple wire from the ignition switch on the one that doesn't crank and see if it will then crank over. It won't start, just trying to get the engine to crank then move to the next step if it does.