2008 DF250 - Electrical issue with PTT and starter

[holder45]

I'll do my best to describe what has happened and the troubleshooting I've completed.

What happened:
Engine is regularly maintained and used weekly. Ran a couple of hours on Wednesday, no problems. Flushed after use, stored on lift. Saturday morning, I tilt the engine down and attempt to crank. Just after turning the key, I heard an audible pop-- I thought I'd blown a fuse.

Symptoms:
1. Power tilt/trim does not operate. When activating up or down from both the remote or switch on the engine, the PTT motor does not activate. However, the PTT relay does click
2. Starter motor does not operate. When trying to crank the starter does not engage, but starter motor relay does click.
3. When ignition switch is turned to ON (not START), the self diagnostic system does not complete-- the lamps on the gauge flicker and the buzzer flutters. Not the usual 2 second beep with all 4 lights on. When the ECM main relay is removed, the full beep returns and the lights illuminate as normal.

Troubleshooting so far:
-Confirmed full charge on battery.
-Inspected all connections from battery through to engine and to electric parts box in engine. All are clean and tight.
-Removed and inspected all fuses: 60A main and 30A sub in engine and 15A in line between ignition and engine. All fuses are good and show continuity.
-Removed and inspected PTT relay, starter motor relay and ECM main relay. All test OK and are within specified resistance ranges.
-Confirmed full voltage to engine and through to downstream of fuses.

I'm hoping someone with more experience can point me in the right direction here. Basically, I'm getting power to the engine and through the relays, but neither PTT or starter are operating. The onset was very sudden with no obvious cause.

Looking forward to hearing your thoughts on next steps to track this down.

[bellatory]

Hmm. Seems like a complex problem. Too bad I cant help you with that. But hold on for other guys to see your problem. Surely someone her will come up with a solution.

[holder45]

Thanks, bellatory. I'm sure it's something very simple and blatantly obvious . . . to everyone but me.

Now that I've had time for it to sink in, I'm going to retrace everything to ground. Since everything on the + side has checked out and the relays activate, I'm thinking there must be some short to ground that I've overlooked.

Always open to other ideas, too.

[Harper]

Could you tell the location of that pop you heard when all this started? Was it at the console (behind the dashboard) or at the motor?

[holder45]

Mike,

Definitely coming from the direction of the engine not near the console.

[Harper]

Another question (I don't have any ideas yet, but am trying to clarify your observations).........

You stated that you attempted to crank, and followed with the statement that when you turned the key, you heard the pop. Am I correct to assume that the pop occurred when you turned the key to "start," rather than when you simply turned it to "on?"

[holder45]

Yes, Mike. When I turned the key to START is when I heard the pop.

[Harper]

Look, I'm kinda talkin' through my hat here, because I don't own and haven't any experience with the 250....I have a DF150. But in looking at the DF250 parts diagram, one question comes to mind. You mentioned that you've checked and discounted any problems with the 60A and the 30A fuses. These fuses, along with a number of other fuses on the DF150/175, are located in a fuse box located on the port side of the motor in front of and below the starter motor. I'm not sure where they're located on your motor, though you obviously know where they are. You also checked the inline 15A fuse. That fuse should be the one on the white sub battery cable to the ECM relay. In perusing the parts diagram for your 250, there is a fuse shown, that is not in any fuse box, and it is listed as a slow blow fuse. The amperage rating is not given. There is no corresponding fuse like it on the DF150.

So I'm just wondering if this fuse might be your problem. It seemed to me from the beginning that your problem might be a blown fuse somewhere, and this slow blow is part of the main harness. You can find the diagram and the fuse that I'm talking about here 2008 DF250 Suzuki Marine Outboard HARNESS Diagram and Parts It is item #26.

Kind of hard to tell exactly where it is on the motor, but I'm sure you can find it. Also, have you tried to turn the motor by hand, just to make sure it is not locked for some reason? And you don't mention removing the starter motor and doing a bench test on it, seeing if its components are functioning properly by connecting the battery directly to the + terminal on the motor and the battery negative to the body of the motor. Could be a faulty magnetic switch there. But the puzzler to me, is that problems in these two areas wouldn't disable the PTT, which is why I brought up the slow blow fuse. It might affect everything on the motor. There should also be a 10A fuse for the PTT motor, but that wouldn't affect the starter circuit.

Don't have any other ideas at the moment.

[Spark66]

Just helped a friend with very similar issue..
be sure and check the main 12 volt supply cables for the motor.
they are typically found near the transom of the boat.

find the large terminal block for the large - and + and inspect.
hope this helps.
Spark

[artdf175]

A pop in my mind is a lose wiring connection
Since you hear the relays the circuit break would be after wiring exits the rectifier/regulator
Two places to check. The 10 amp inline fuse to ptt
In same check list tells you to check white/red lead wire of main harness and "B" terminal of starter motor magnetic switch
A fairly heavy power line with a end cover over terminal it connects with starter motor switch
Since you indicate checking 10a fuse -I would take that starter connection apart and check for arcing or a burnt connection
Art

[artdf175]

Had one other thought.. re your symptoms #3
what you are describing is sounding like a short circuit.. someplace on the output side of the ECM
get the wiring diagram and start tracking down where it runs
since you got a big pop when it happened.. it is to be one the main wires.. one of the smaller unfused wires would have probably just melted..
Again.. since it is affecting both the starter and PTT would check both ends of the main lead to the starter motor switch..
===
and I have one other thought.. two years ago I had a wiring problem with the main power lead between the power supply switch (battery --on off or both ) and all systems on the dash including motor key start ... at first it seemed somewhat of an intermittent electrical problem..
one day in my driveway.. everything just quit.. thank goodness it was the driveway.. took me a while to track it down
the wire coming off battery switch has a short pigtail with the connector between it and the main power wire that feeds the dash etc..
the wire inside the connector just corroded away.. in running down each wire, the second or third time I pulled on this one.. just came apart in my fingers.
just something else you might check while you are at it..
Art

[holder45]

After plenty of frustration and head scratching, I read Spark's comment and went back to check the main battery cable ground at the transom. While it wasn't visibly that bad, I completely removed the connections to clean them.

The negative connection had some corrosive buildup on the under side, but nothing that I thought would be the culprit. It was. After cleaning that lug back to shiny metal and a nice coat of dielectric silicone (JetLube brand in the 1-lb can is great stuff BTW), bam-- all systems go. An old mechanic once told me that 99% of DC issues trace back to a grounding problem. Looks like he (and Spark) were right again.

Thanks everyone for your comments and ideas. It just goes to show how the basics are almost always the answer to electrical gremlins. Another frustrating learning experience under my belt for future reference . . .

[Spark66]

glad you found it..