2012 LF150XA cranks but won't start - possible relay issue?

[supergroove]

Hello all!
We're taken ownership of a supposedly "lightly used" Yamaha outboard and are trying to get it running. It cranks strong but does not start. After some research it seems the fuel pump doesn't click on when you turn the key on. Further research and reading countless forum posts leads me to believe that it's probably something electrical rather than the high pressure pump itself. I've taken the fuse panel out and cleaned it after I realized how BADLY corroded it was (we live in Hawaii and the outboard was on a boat in a slip and then sat for a while). The fuses were really corroded so I replaced them. I bench tested the relays as per the manual (connected to a battery and Ohm meter) and neither show continuity so I'm thinking they are probably both bad. One of them makes a weird continual click/pop noise when connected to power (the other doesn't make any noise).
Screen Shot 2020-03-25 at 12.58.53 PM.png


I get the feeling that the ECU isn't talking to the motor or tach/gauge. Just trying to start out with the simplest thing first. We live in Hawaii and it can take quite a bit of time and $$ to get parts and I'd really like to avoid just throwing money at the motor on things that may not be broken.

So my question are as follows:

1. It's hard to get parts here on the Big Island without waiting for a week+ and with this current pandemic we're supposed to stay indoors. That said, is there a compatible automotive relay that might work that we can get at O'Reilly or Napa?
2. Would it make more sense to find a lightly used fuse panel on eBay (that already has all the fuses and relays intact) or buy a couple new relays? Just buying two new relays is about the same price as getting a whole new-used fuse panel and having an extra panel would give us extra fuses and options to switch things out and trouble-shoot things.
3. The last question is then, would any later model Yamaha fuse panel work or do I need to get the exact part number that boats.net shows? There aren't many options for my exact outboard on eBay.

Boats.net shows the part I need being 63P-82170-00-00 (https://www.boats.net/product/yamaha...SABEgIJU_D_BwE)
I found this one on eBay (part # 68F-82170-01-00) - seems to be for older model outboards (https://www.ebay.com/itm/2002-Yamaha...kAAOSwXedcJ5ca)

I'm reluctant to spend a bunch on new parts if I don't even know if this is the real issue, or just the start of a series of bigger issues. We're starting to feel like we had a "fast one" pulled on us by buying this outboard. Anyway, we would greatly appreciate any advice or suggestions for troubleshooting things.

Thanks!

[DennisG01]

Does your boat have a "kill" switch? A switch of some type that is usually connected to a lanyard that we can attach to us. Sometimes the clips that "slip" into the kill switch can get partially broken, thereby not really releasing the "kill" feature.

Sorry - didn't read your initial post as well as I should have and missed the part about you testing the relays. If you're able to with your setup, can you bypass the relays with some heavy gauge wires? Does that allow things to work? I'm more familiar with doing this with Mercruisers, so I'm sorry that I can't offer any specific advice here - but maybe it gets you going in the right direction to double check things?

[supergroove]

Thanks DennisG01 for your reply! The controls are new and so is the tachometer and harness... I verified that the buzzer works but not the kill switch. I'll look into that.

Yeah it did cross my mind to try and "jump" the relay... not sure which two connections to connect a wire to though... maybe someone can chime in? Much appreciated!

[DennisG01]

Based on the picture you provided, it would be C & D. Key on power (battery power) would cause those two pins to close (connect), supplying power to the pump. Thinking more about this... basically, just connect C & D together. I don't know if cutting a spade electrical connector off would be big (long) enough to connect the C & D female spades together - but basically, you just need a piece of metal that both of them will slide onto. Maybe a wire with alligator clips would wok?

[fairdeal]

I bench tested the relays as per the manual (connected to a battery and Ohm meter) and neither show continuity so I'm thinking they are probably both bad. One of them makes a weird continual click/pop noise when connected to power (the other doesn't make any noise

I'm baffled - two relays?

You obviously have the Service Manual, you've posted an excerpt from it -
there is one Main Relay -
what is this second relay?

[supergroove]

Thanks for chiming in. The fuse box contains extra fuses and relays so the second one I mention was a spare. To reiterate, the fuse box was really corroded when I started pulling fuses salt water corrosion was visibly coming out as white powdery granules.

[panasonic]

Could you post a few pictures of the corroded fuse box you have? You may be able to clean up the corrosion to make it serviceable again.

As for the eBay fuse box..it may very well fit,BUT until you have in your hands to compare it to your old one then it’s a crap shoot.

If it were my engine I would try and clean up the fuse box and replace the relay and see if this cures the problem. If it does then you can think about buying a new fuse box for peace of mind.

What about the connectors and plugs that go to the fuse box....are they corroded as well? If the fuse box is as corroded as badly as you say, I would suspect that this engine may have been “sunk” sometime in its past. I would suggest checking all connections on the engine for corrosion.

[DennisG01]

SG, I had something else in my mind when I was responding on how to jump the relay. Disregard the "way" I said to do it with spade connectors since that relay "plugs" into slots? Instead, just get a short length of wire and put two male spades on it and plug them into C & D. You probably already figured that out, but just wanted to mention that since my post was a little confusing.

[robert graham]

Thanks for chiming in. The fuse box contains extra fuses and relays so the second one I mention was a spare. To reiterate, the fuse box was really corroded when I started pulling fuses salt water corrosion was visibly coming out as white powdery granules.

Sounds like a lot of salt water corrosion.....this motor hasn't been submerged or run without the upper shroud has it???

[supergroove]

Thanks panasonic for your input, appreciated! Yeah I did take the fuse box apart completely (don't have photos of it before I went to work on it unfortunately), and gave it a good careful once over with a wire brush, some sandpaper, and then cleaned things up with some CorrosionX and then wiped everything mostly dry. It felt OK when I put it back together... there were a couple wires at positions 8 and 21 in the main fuse box harness that came out but I cleaned them up and glued them back in and they seem to have continuity to the ECU now which makes me think all is well. The back of the fuse box connectors had some corrosion but also were covered in some decent thick grease so the wires seem good. We don't suspect the motor was submerged, but it does feel like there might have been some saltwater condensation on the fuse block and then it sat a while.

DennisG01, thanks again for clarifying. I actually did exactly what you recommended yesterday with a wire and two male pins and it didn't seem to do anything. I put the "spare" relay in and got some battery voltage readings, but the test for voltage with the controls ON and testing A-B still produced no power at all (see the screenshot below from the manual). We're going to look around today and see if we can find a relay at an auto parts store that is compatible... if not we'll have to order on eBay and wait a week to try again.

Screen Shot 2020-03-26 at 11.44.01 AM.png

Definitely appreciate your help!

[supergroove]

So I think I'm making progress on all of this... but still can't get the high pressure fuel pump to turn on. I bought a new (automotive) relay that passes the bench test and the fuse panel now passes the rest of the tests in the manual. I also applied power directly to the high pressure fuel pump and it DOES turn on and make noise. Looking at the very last few pages of the manual it shows a wiring diagram for the "Engine control unit and fuel unit" (see screenshot) and it shows that pin 12 on the fuse panel should provide power to the high pressure fuel pump. I've run continuity tests and it's actually pin 13 that provides power... so the manual is wrong or (as the Seloc manual states), pins with the same color wires are interchangeable!?!?

yamaha-diagram1.png

Dropbox link: https://www.dropbox.com/s/gnkmiywzkt...gram1.png?dl=0

The bottom line is that with the control switch turned to ON, it does NOT provide power to pin 12 or 13 of the fuse box to turn on the high pressure fuel pump. I've scoured the manual but don't see any other way to test the fuse box but at this point I think that must be the problem. I went ahead and ordered one off of eBay that looks to be much less corroded than mine. Fingers crossed that fixes the issue.

FYI: I subscribed for full access to the Seloc manual and are making sure all diagrams are up-to-date and the pins I'm testing are indeed the right ones.

I'd totally appreciate any other suggestions or feedback. This has got to be one of the most frustrating things I've had to troubleshoot in years... my gut tells me it's a simple issue but it still has been taking hours every day and it feels like no progress is being made.

Thanks!

[99yam40]

you do know that even if + 12V gets to the pump, the ecu closes the ground to make it run when the ecu wants it to

have you checked the wires at the pump to see if + or - is getting to them when you turn on the key?

[supergroove]

Hey 99yam40! Thanks for your input. The pump is not getting any power, not at key start or any other time. I've tested that with two different ECU's and two different main relays. The reason I am stuck on the fuse box is that if it's not sending power to the high pressure pump, even if the ECU grounds the blue wire, it still won't run. The fuel pump needs both power and ground. Anyway, hopefully a new fuse box helps... or we will be stuck with driving 2+ hours to take the boat+motor to the other side of the island for the dealer to check things out. We're really trying to avoid that. It's possible that there are other issues causing the fuse box not to send power... any ideas? Thanks in advance!

[supergroove]

Update: a new/used fuse box fixed the issue and the fuel pump turns on when you turn the key to one click. Unfortunately the motor still won’t start... so the troubleshooting continues.

[99yam40]

is there spark at all or any of the plugs?

is the rail pressure in spec?

running the high pressure pump without fuel in the VST can hurt that pump as the fuel acts as a lube and cools the pump/motor as it runs thru it.

as always when working on a motor, I check to make sure there is good compression and then spark, and then if those are good chase fuel problems