Yamaha F150 won't start and trim

[Bilge Rat]

Basics.
A weak connection between the power source and the load will allow 12 volts to be present and the motor at rest.
When you try to start the motor it needs power, amps.
The weak connection is resistance.

Ohm's Law

Look it up, it will help in understanding electricity.

I say this in a helpful way.


A bad battery switch will sometime work fine and the next start you get a weak battery sound.
It is a moving electrical part in saltwater.

[Moskvich]

IMHO, check the basic's first... Especially the fuses(easy enough)

Your kinda getting ahead of yourself looking for the worst case scenerio. In most cases, the problem is the weakest link, that aftermarket switch.

Fuses are all good, than next step should be checking battery switch. It hasn't contact with saltwater (boat is in river), but it is possible that something went wrong with that switch...

BTW, that relay, to my knowledge, is NOT CHEAP at all.

Yeah, it isn't cheap at all. In USA it costs about 150$, here in Croatia (Europe) it's about 460$. Real horror.

[TownsendsFJR1300]

Any updates?

[Moskvich]

Any updates?

I removed that main relay from engine and delivered it to electrician on examination. He said that solenoids (is that right word in English?) are bad and broken (disconnected somewhere). He is putting new solenoids on relay and I hope so that this will be done tommorow. Then I will put it back on engine and try again, hoping that this will remove my problem. I will post new informations about problem, thank you very much for your help and assistance.

[Moskvich]

News: relay is back on engine. Connected and first time trimmed engine a little bit up successfully. Then I tried to start engine, cranked and just strange noise (like fast clicking or buzzing) from that relay. Then tried to trim engine up or down again, but nothing. When I hit trim button on engine or on throttle box I hear just click from that relay. Hit button and just sound - click, nothing else.

Again strange situation. First time it managed to trim engine, and after that nothing, like dead. Battery standby voltage - 12.7 V, both, measured with voltmeter - 9 V displayed on speedometer. Everything else working, engine dead. Strong connections on battery and on engine.

[TownsendsFJR1300]

I'd be curious as to what the actual voltage DROPS TO at the starter itself when cranking it over. There's a heavy lug on the starter to put a volt meter to, ground it to the block.

My gauge cluster, when starting cold (for an F150) show's voltage dropping to the low 11 volts. 9 volts is pretty low, why its that low is likely the issue.

Re the battery switch, it doesn't have to be wet to wear out. Just the marine enviroment, wear and tear, wear things out. Perko is popular but isn't known to be the top of the line.


Were you ever able to by pass the battery switch altogether?

[99yam40]

Some battery cables and other wires can go bad internally, so need to use hand held volt meter to test where you have good voltage and where you do not while under load.
The negative can be a problem as well as the positive, so start testing

[Moskvich]

I'd be curious as to what the actual voltage DROPS TO at the starter itself when cranking it over. There's a heavy lug on the starter to put a volt meter to, ground it to the block.

I should check voltage on starter when cranking engine, how could I measure voltage on starter with voltmeter like this one: http://ebay.prnc.net/Resources/voltm...05-320x332.jpg.

Where should I put those voltmeter 'needles', looking on this picture: http://www.thehulltruth.com/attachme...nty-f150.4.jpg

Re the battery switch, it doesn't have to be wet to wear out. Just the marine enviroment, wear and tear, wear things out. Perko is popular but isn't known to be the top of the line.


Were you ever able to by pass the battery switch altogether?

That is also remaining to do, to check that battery switch. I don't think that problem is in it (it was working perfect, and then 'during night' it's dead, how is it possible?) but maybe I'll get surprise, maybe problem is there. I must visit boat directly with my electrician, he could check the battery switch.

By by pass you mean to disconnect engine wires from switch and connect them directly to battery?

[TownsendsFJR1300]

I mean disconnect the main Yamaha battery harness from the switch and ground (the main battery lines that come out of the engine and goes to your battery) and hook it direct to a known, good battery. (positive and negative and take the battery switch OUT OF THE EQUATION).

That battery switch is the weakest link. Corrision occurs, contact pressure lessens, etc.. IMHO, I'd be starting there.


Why did it fail suddenly(if it has)? Why does anything fail suddenly. It has a designed working life. Same as any battery, the car wouldn't start this morning, ran fine yeaterday, why did it die overnight, just wear and tear...

[Bilge Rat]

Sounds like the relay damage is just a victim of the real problem.
A weak connection is lowering the voltage which raises the amperage required to turn the starter.
This high amp draw is burning up the relay.

Ohms law.

The battery switch works? yes it moves and yes it turns OFF. Yes it turns ON but the contacts are weak.
If you measure voltage across it it will read 12v just fine BUT it will not allow enough power/amps to pass UNDER A LOAD such as engaging the starter and still maintain anything close to 12v.

Unhook the battery cables from the motor. Take a good battery that has nothing hooked to it and a set of jumper cables.
Hook the cables to the motor then directly to the battery and try the starter.

Rebuilding a relay can be done but is not ideal.

[Moskvich]

Unhook the battery cables from the motor. Take a good battery that has nothing hooked to it and a set of jumper cables.
Hook the cables to the motor then directly to the battery and try the starter.

Can you please show me which cables should I unhook and where to connect jumper cables? http://www.thehulltruth.com/attachme...nty-f150.4.jpg

I guess the first big black cable looking from left to the right, and other?

[TownsendsFJR1300]

Can you please show me which cables should I unhook and where to connect jumper cables? http://www.thehulltruth.com/attachme...nty-f150.4.jpg

I guess the first big black cable looking from left to the right, and other?

Yes, the large cable to the block goes to ground, NEGATIVE (or put your ground cable there).

The other attached cable, is the positive. You have to slide the rubber cover off and down to gain access to the terminal. Hook up the positive jumper cable to that and your ready to go!

NOTE: Just run the jumper cables to that terminal and ground bolt(make sure their clean and very snug. Just try to get a good connection. Your basically jump starting your outboard engine vs jump starting your car battery..

BTW, both of those cables, where they attach should be spotless clean and very snug. If their slightly loose, corroded, that could be your issue itself.

I would strongly suggest investing in some "Di-lectric grease". Its used for electrical connections to keep water, moisture, corrosion out. I use it on battery terminals, any electrical connectors I pull apart, bulb bases, etc. It'll prevent any future corrosion problems..

[Moskvich]

Yes, the large cable to the block goes to ground, NEGATIVE (or put your ground cable there).

The other attached cable, is the positive. You have to slide the rubber cover off and down to gain access to the terminal. Hook up the positive jumper cable to that and your ready to go!

So, positive cable should be connected from positive pole on battery to place where is cable with the rubber cover. Negative cable from negative pole on battery to place where another big black cable is, a little bit beneath from starter?

BTW, both of those cables, where they attach should be spotless clean and very snug. If their slightly loose, corroded, that could be your issue itself.

They are already clean, without any corrosion, and greased, everything in perfect condition.

I would strongly suggest investing in some "Di-lectric grease". Its used for electrical connections to keep water, moisture, corrosion out. I use it on battery terminals, any electrical connectors I pull apart, bulb bases, etc. It'll prevent any future corrosion problems..

I'll try to find that grease somewhere and put on contacts between engine and batteries.

[99yam40]

Simple voltage drop test with meter will show if there is a problem and where.

[TownsendsFJR1300]

Simple voltage drop test with meter will show if there is a problem and where.

That was mentioned earlier in posts 5 & 6 and numerous posts after that.

Seems the Op and his mechanic are not very familar with just the basic wiring (no offense intended)..