"White Wire" Power failure

[boats.net]

Thanks to Artdf175 for this post
subj: "White Wire" electrical issues -power source to the ECM

When you turn the ignition switch and nothing happens. (Battery fully charged)

This is one issue that surfaces on a regular basis and this generally deals with a loss of power source to the "engine control unit" (ECU).
With NO power to the ECM, the engine either stops (if running at the time) or will not start.
This situation usually effects the trim switch on the remote, which also fails to function.


Some background:
Generally, the battery switch (Perko type) has a short pig-tail with a connection to a "white wire" (WW). This WW feeds the power to the ignition and remote control trim switches. In some wiring configurations it can also be the power feed to the dash that powers up the boats other electronics. Note - this WW also has an inline 15A fuse. The WW can be connected directly to the positive battery terminal. Have found it can be tied into the main power lead to the engine, on the starter motor. (not recommended as this configuration can cause electrical spikes to the ECM.)
The WW splits pre-ignition switch and powers the ECM relay coil.
From the ignition switch "ON" position, the gray wire feeds back to the ECM -and is the power source for the ECM.

First let's look at the trim switch.
You hit the remote trim switch to trim the engine up/down and nothing is working. The wiring to the trim switch relay is independent of the ignition wiring but shares the same WW power feed. This allows you to raise and lower the engine without turning on the ignition. When it doesn't work- the cause will usually be related to a power failure with the WW. It can be the switch, but that seems to be rare. The trim switch on side of the engine operates independently from a different power source.

Next: turn the ignition to start/run - no response.
The ignition switch does several things- in the 'ON' position it is the primary power source to the ECM. At this point, for 4 cycle engines, a relay turns on the high pressure fuel pump. You should hear this pump. Obviously when the key is turned to 'START'- the starter relay engages and through the engines main power source, the starter motor starts the engine. One step before the starter kicks in, the 'neutral' switch must be adjusted correctly, so as to prevent the engine from starting if it is in gear. However, any interruption in power to the WW- none of this happens.
.
So what has gone wrong when these two situations happen? Usually - a lack of continuity of power in the WW or a ground wire failure.

Most common Reasons:
1) Spliced connections that have gone bad. Connectors not waterproofed that allow for unseen corrosion.
2) Wiring connectors have separated
3) Ground wire fails.
4) blown fuse

If you have power to one and not the other:
5) Ignition switch that has become defective or broken
6) If you have power to the ECM and starter fails to kick in, one of several more reasons can relate to the neutral switch.

Intermittent power loss can be difficult to find.. In my case, the wire connector to the WW off the battery switch started to fail. I would be running along, hit a wave and the engine would die. Or come up to a dock and put it in idle .. just dies and not start. Again, in my case, the WW is the power source to the dash and other electronics. The depth finder would flicker off, sometimes come back on, but mostly have to restart it. Then one day in my driveway, nothing worked - period. Started pulling wires to track and identify each one and what did they operate. Pulling on a short red wire off the back of the battery switch - the wire connector separated.. This was the power feed to the WW. Internally inside the wire connector -the wire ends were totally corroded at this point. Fixed the problem and was back in business.

- update Nov 2017-
thanks to Catislaguy there is updated info for some smaller HP models
He has a 2009 DF115HP
The primary WW off the battery to the key switch is the same but that is also where it stops.
The ECM in this smaller HP engine is powered of the Hot wire on the starter motor. Connects to the same terminal where the primary battery cable terminates.
The 'on' and 'start' position of the Key Switch - power goes to the Gray wire. The Gray wire then proceeds to power just about everything on the engine, but the ECM.
So if you turn the Key Switch -on- and nothing happens -- still need to start with #1 - fuse box; then #2 the WW; #3 the key switch itself; #4 is the Gray wire hot? if so the engine should run. If not - go back to #1 and start over.
This person, from a separate fuse panel, wired around the WW and everything worked -but why?
Answer was the ECM power source is different.
Art





Hope this little summary will be helpful..

[Nayna32]

Great post!!! I'm glad I know what the white wire is for now, and what symptoms its failure can create!

I was inspecting the installation of my DF140a. I found a fused white wire connected to the starter that was looped several times because it was several feet long and tie strapped together; then went to a single bullet connector in the engine harness. It looked out of place. While moving the wire around to trace it, the wires strands came out of the blue automotive crimp connector.

I couldn't find a fused white wire coming off of the starter in the wiring diagrams. I knew it was there for some important reason, so I shortened the wire several feet, solder the bullet on and heat shrinked the end. I was going to post asking if anyone knew what it was for.

Now I know why the wire was that long, so it could be connected to the battery switch. They ran it off the starters power terminal and used the connection in the motors harness to power the ECM and other sensors. So I figured out the white wire can connect to the console harness or engine harness; probably whichever is closer to the battery switch. Glad I fixed it before it fell out on it's own. I possibly could have had a break down on open water, and had no clue why.

Thanks for the post!

[tnadeau]

WW connected to starter + instead of Battery

If the WW is connected to the starter + post then your remote trim switch on the outboard doesn't work with the ignition switch in the “off” position, correct?

[Nayna32]

It still works like it is suppost to. When the battery switch is on; power is supplied to the starter, which powers the WW, PTT relays, and I'm sure other components, regardless of ignition switch position.

The wire would have been connected to the other end of the starter wire at the battery switch which would perform the same function. They saved time and aggravation by simplifying the wire routing.

[Moonlighter]

It still works like it is suppost to. When the battery switch is on; power is supplied to the starter, which powers the WW, PTT relays, and I'm sure other components, regardless of ignition switch position.

The wire would have been connected to the other end of the starter wire at the battery switch which would perform the same function. They saved time and aggravation by simplifying the wire routing.

Yes it works.

No, it is NOT the recommended method from Suzuki. The ECU is sensitive to voltage and the risk is that the starter will expose it to voltage drop.

[Nayna32]

Thanks Moonlighter. That makes sense. I was wondering why they did this, and was having a dull brain moment. Unfortuantely, this adds another check to my disappointing installation.

It's the same reason I moved my electronics off the start battery years ago after purchasing my boat. Looks like I will be correcting this in the very near future.

[LG-Pontoon]

This forum was great in helping me find my "white wire" problem with my DF40 pontoon boat. Turned out to be a bad splice in a cable run from the motor under the boat to the console and remote.
Thanks to all the contributors!

[artdf175]

This forum was great in helping me find my "white wire" problem with my DF40 pontoon boat. Turned out to be a bad splice in a cable run from the motor under the boat to the console and remote.
Thanks to all the contributors!

Perfect feedback
Thanks for sharing
Art

[artdf175]

http://www.suzukioutboardforum.com/s...ey-switch.html

Info at bottom of the thread re wiring colors and circuits

[a7ewizard]

Mitigating ECU power lead failures.....

I just finished installing and rigging my new 2017 DF300AP. My installation was an I/O to bracketed Suzuki conversion. I had read threads on various forums regarding "White Wire" failures (as talked about in this thread).

One of my goals in this conversion was to also separate the electricals into 2 separate circuits; an engine circuit and a house/electronics circuit. Previously, everytime I started my engine, my GPS plotter/sonar would die and needed to be started. That was very annoying.

The ECU power leads are very thin (maybe 22 gauge) and have connectors to fit the threaded terminals of marine batteries. Battery terminals are the most corrosion prone point of the entire system and to connect these thin leads here is asking for trouble IMO. There must be a better way........

So, here is how I rigged my engine and I have encountered no problems:
I used a Blue Seas dual circuit battery switch with the combine batteries option (should the house side need to jump the engine side). I mounted this high on the transom with a separate access panel. Along with the main engine positive lead, I connected the white wire lead to the same post. Thus, the ECU is only hot when the battery switch is turned on. The engine trim only works with the battery switch on (at engine) and works with the key switch on (at throttle). Since my battery switch access is so easy, this is not an inconvenience to me.

The ECU ground lead I connected to the negative side of the buss bar; that is also mounted high on the inside of the transom to reduce exposure. Since this is a ground, it doesn't matter that this buss is on the house side. In fact, for a dual battery installation, the Suzuki rigging manual has the 2 battery negative terminals connected to each other.

The pink auxiliary charging lead I connected to the house/electronics post of the battery switch. While I could have simply connected this to the corresponding battery terminal, I choose to cut the excess cable and to tidy up the installation. I used a voltmeter to check the charge at both batteries and there is negligible difference.

Finally, because I might have to combine the batteries in a dead engine battery situation, the house/electronics circuit needed to be stout enough to tolerate a heavy starting load. For this I ran 2 gauge cable from the house battery positive terminal to the battery switch post for this circuit.

I shortened the engine cables and added crimped terminal connectors with shrink wrap. I avoided the coiled and wire tied excess cable look to the maximum extent possible. I did not shorten the "white wire" for simplicity and beacause it is largely out-of -the way and stowed near the top of the electricals.

I wanted to share my ideas and outcome should this be of help to some one else.

Warren

[artdf175]

Warren. thanks for the time and input.
just a couple of thoughts. and I do not know the circuit panel you used except from comments from others that give it very high marks.
a couple of observations
the white wire should terminate at the key switch - when you turn the key to the 'on' position is when the power then travels back to the ECM
the whitewire should connect at your circuit panel and not directly off a battery post
at the bottom of this link there is some info on the wire coloring:

http://www.suzukioutboardforum.com/s...ey-switch.html

there is a reason for the white wire not being connected to the main power source for the engine. The ECM is very sensitive to voltage drops. Voltage upon starting can can give power fluctuations that may be undesirable

Your power trim on the remote is designed to work regardless of the key being in the on position. you may find a time when it is undesirable to turn the key on just to raise/lower the engine

Art

[Catisleguy]

Is my "Fix" wrong?

Thanks to Artdf175 for this post
subj: "White Wire" electrical issues -power source to the ECM

When you turn the ignition switch and nothing happens. (Battery fully charged)

This is one issue that surfaces on a regular basis and this generally deals with a loss of power source to the "engine control unit" (ECU).
With NO power to the ECM, the engine either stops (if running at the time) or will not start.
This situation usually effects the trim switch on the remote, which also fails to function.


Some background:
Generally, the battery switch (Perko type) has a short pig-tail with a connection to a "white wire" (WW). This WW feeds the power to the ignition and remote control trim switches. In some wiring configurations it can also be the power feed to the dash that powers up the boats other electronics. Note - this WW also has an inline 15A fuse. The WW can be connected directly to the positive battery terminal. Have found it can be tied into the main power lead to the engine, on the starter motor. (not recommended as this configuration can cause electrical spikes to the ECM.)
The WW splits pre-ignition switch and powers the ECM relay coil.
From the ignition switch "ON" position, the gray wire feeds back to the ECM -and is the power source for the ECM.

First let's look at the trim switch.
You hit the remote trim switch to trim the engine up/down and nothing is working. The wiring to the trim switch relay is independent of the ignition wiring but shares the same WW power feed. This allows you to raise and lower the engine without turning on the ignition. When it doesn't work- the cause will usually be related to a power failure with the WW. It can be the switch, but that seems to be rare. The trim switch on side of the engine operates independently from a different power source.

Next: turn the ignition to start/run - no response.
The ignition switch does several things- in the 'ON' position it is the primary power source to the ECM. At this point, for 4 cycle engines, a relay turns on the high pressure fuel pump. You should hear this pump. Obviously when the key is turned to 'START'- the starter relay engages and through the engines main power source, the starter motor starts the engine. One step before the starter kicks in, the 'neutral' switch must be adjusted correctly, so as to prevent the engine from starting if it is in gear. However, any interruption in power to the WW- none of this happens.
.
So what has gone wrong when these two situations happen? Usually - a lack of continuity of power in the WW or a ground wire failure.

Most common Reasons:
1) Spliced connections that have gone bad. Connectors not waterproofed that allow for unseen corrosion.
2) Wiring connectors have separated
3) Ground wire fails.
4) blown fuse

If you have power to one and not the other:
5) Ignition switch that has become defective or broken
6) If you have power to the ECM and starter fails to kick in, one of several more reasons can relate to the neutral switch.

Intermittent power loss can be difficult to find.. In my case, the wire connector to the WW off the battery switch started to fail. I would be running along, hit a wave and the engine would die. Or come up to a dock and put it in idle .. just dies and not start. Again, in my case, the WW is the power source to the dash and other electronics. The depth finder would flicker off, sometimes come back on, but mostly have to restart it. Then one day in my driveway, nothing worked - period. Started pulling wires to track and identify each one and what did they operate. Pulling on a short red wire off the back of the battery switch - the wire connector separated.. This was the power feed to the WW. Internally inside the wire connector -the wire ends were totally corroded at this point. Fixed the problem and was back in business.

Hope this little summary will be helpful..

Question, as stated above,

The WW "splits pre-ignition" switch and powers the ECM relay coil.
From the ignition switch "ON" position, the gray wire feeds back to the ECM -and is the power source for the ECM.

If this is correct, then should I assume I was wrong when my fix was to disconnect the WW at the fused connector and abandon and terminate it before the ignition switch, and then power the WW before the switch with a 15 amp fused wire from my panel?

Does this mean my ECM relay coil has no power now and before it Always had power regardless of the ignition switch?

[artdf175]

I don't want someone to think I ignored your questions.. but we did it through a PM..
Art
update Nov 17
this owner has a 2009 - 115HP
he did not find the problem -exactly- but by wiring around the original WW, through a separate fuse panel to the WW on the key switch - he was back up and running
This model is wired differently than the larger HP engines
Updating the original 'sticky' to reflect this new information on the wiring
Art

[TxAg66]

Probably a dumb question but is an ECU (engine control unit) the same as an ECM? I saw both terms used in the very first post &, after that, only ECM has been used. Just wondering. And trying to learn. Thanks..
John

[Harper]

Probably a dumb question but is an ECU (engine control unit) the same as an ECM? I saw both terms used in the very first post &, after that, only ECM has been used. Just wondering. And trying to learn. Thanks..
John

Same thing, John.