2009 DF175 Trim kills engine

[Doug2179]

Hello, I am new to the forum and looking for some advice.

I recently purchased a used boat with a 2009 DF175. About the second time I ran the boat, I noticed the engine died at the exact time I was trimming it. Would not start from the key on position, had to turn to off to restart. Then the following weekend the same thing, but could not make it due it when I tried several other times. After that I went and cleaned all battery connections. I have 2 batteries, normally run on 1.

This past weekend I had the boat out and one time after running for about an hour, it died again. So later in the day it would die everytime I hit the trim.

Any ideas as to what to start checking first? The voltage at the batteries both say 12+. I also placed the batteries on both this weekend with the same results. Did not have capabilities of checking this weekend with everyone on boat, but would like to start looking into the issue.

Thanks

Thanks

[ChrigelKarrer]

This sounds to me as you have weak batteries and while using the trim motor the power drop too much to power the ECU.
You may try to use one, known good battery and try it again to see if the problem persist.
If the problem persist you should measure the voltage while trimming;
if the voltage is above 11 volts it should be fine and the problem is elsewhere
if the voltage drop below 11 volts you have a battery problem or your trim motor uses a much too high amount of power.
If your batteries seem to be fine then you have to start to track electric gremlins and this can be a nasty job. First you may check your negative cables!
Chris

[Doug2179]

Thanks Chris

I think I am going to pull both batteries this week and have a load test ran on them, if that checks out then start to follow wires looking for possible issues.

[redlowrey]

Thanks Chris

I think I am going to pull both batteries this week and have a load test ran on them, if that checks out then start to follow wires looking for possible issues.

You don't have to pull the batteries out, connect up a digital multimeter on volts and crank the engine watching the volt meter, you don't want it to drop below 9 to 10 volts, do that on each battery, then do it with both batteries it should not drop below 10 volts on both batteries. If you were capable to start the engine on one battery I don't think you have a battery problem. Start doing some voltage drop tests around your main ignition supply wire, white on a fifteen amp fuse could be coming off your battery pos or from starter solenoid battery pos or from the fuse box. Have a look too at the main wiring loom plug at the engine, it runs up the loom to the ignition key where it is spliced to a white and red wire that go's to your trim. Should not be hard to find.

[Doug2179]

Thank you. I don't believe the batteries are the problem. It has always started on 1 with no issue. I checked the white wiring coming to the ECM yesterday and it had 12+ volts. I will check the batteries with the volt meter this week and I want to check all the trim motor connections and wiring harnesses in the back.

What are you thoughts as to why the trim could kill the motor sometimes?

Thanks agian

[artdf175]

Are any of the other electronics being affected when this happens?
like the depth/gps goes blank and restarts?
It could be that one of the wiring connections is corroded inside the connector that you are not seeing..
I have referred to it as "the white wire" problem
off the battery switch is a connection to the white wire that feeds the ignition switch (sometimes the dash and other electrical components). this wire feeds power through the ignition switch to the ECU.. any disruption in the line voltage to the ECU, kills the engine.
if there is corrosion, you may have only a few strands of wire making contact.
your volt meter could be showing 12 volts but under load it may be dropping below specs.
Art

[Doug2179]

Thanks Art

In looking my system over it seems the white wire to the ECU comes from my perko switch to the 15 amp fuse then directly to the ECU with a connection inside the motor cover. This white wire has 12+ volts with the key off as long as the battery switch is on, so I do not think it goes to the ignition switch first. I need to do some checking as I am not sure how the ignition switch gets power. My thought is that it comes back from the ECU in the wiring harness, but I do not have a diagram so I could be wrong.
Also the accessories such as radio and GPS stay on when the engine dies.
I am thinking I am getting a voltage drop to the ECU when I trim, but not sure.

[wilbur1]

I might of missed it. But did you check voltage while trimming? Could be a bad motor pulling too many amps.

[artdf175]

Thanks Art

In looking my system over it seems the white wire to the ECU comes from my perko switch to the 15 amp fuse then directly to the ECU with a connection inside the motor cover. This white wire has 12+ volts with the key off as long as the battery switch is on, so I do not think it goes to the ignition switch first. I need to do some checking as I am not sure how the ignition switch gets power. My thought is that it comes back from the ECU in the wiring harness, but I do not have a diagram so I could be wrong.
Also the accessories such as radio and GPS stay on when the engine dies.
I am thinking I am getting a voltage drop to the ECU when I trim, but not sure.

Doug
there are two battery leads to the engine.
the one that runs the ECU does come off the white wire, with built in 15A fuse, that runs through the ignition switch. I am very clear on this wiring.
In my boat, that wire also powers the dash, so as I was having intermittent power problems, before it died altogether, anything hooked to the dash was also being effected.
The trim from your remote should also be effected, as that power source is the same white wire.. the trim on the side of your engine, is not effected as this gets its power differently.
so if you are getting momentary stopping of the trim as the engine dies, it would be another clue..
art..