Help new member down

[Wendell11]

I have a 2003 df140 that I just got on a v20 wellcraft. Took it out last night and less than 10 minutes into the ride I got a high temp alarm. Shut motor down to cool for 20 minutes or so fired back up to limp to dock until alarm came back. Let sit again tried to start and heard a pop at the motor and lost all power. Found today the main wire harness is melted. Has anyone had this problem? Does anyone have a harness and how screwed am I with the ecu.

[Moonlighter]

On the early 140’s (pre 2008) there was an issue with corrosion thru the engine holder to the exhaust. This COULD be the cause of burnt harness on your engine.

Take the cowl off and the lower covers. Look on the port side just below where the fresh water flushing attachment plug is. There is a plug in the casing there looks like a round welsh plug. If there is corrosion around that plug that has broken through it can allow hot exhaust gas to escape and burn through the harnesses nearby. And then you get false alarms….

If that is the problem, then repairing the burnt wires should address that issue, and then you need to attend to the corrosion - some have had good success in getting a skilled aluminium welder to remove that plug and weld a patch over the hole.

If the damage is elsewhere I cant offer anything more. Perhaps you could take some photos of the damaged wiring and post them here, that will help people to offer other suggestions.

[Wendell11]

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[briscoe]

Well, it's looks like you don't have an engine holder corrosion hole, which could have caused your "smoke" alarm. Disconnect the battery and open wire bundle and see what caused it. Sounds like main power supply wire went to ground. Who could say on ECU, yet.

[Wendell11]

Well being an electrician by trade I intend to fix the harness and give it a shot. Fingers crossed it didn't hurt anything else.

[redlowrey]

Have a look right where that hex plug is and see if there is a small hole beside it, because that loom runs right beside it. that plug is what you remove to install an 02 sensor to check the air fuel ratio it is a steel plug and the aluminum corrodes beside it.

[Wendell11]

Ok update hole in plug was huge. It has been repaired and motor pot back together but I seem to not be getting fuel on cylinder 2 and 4. If I move cylinder 1 injector harness to 2 I believe it works. So I would assume the ecu is probably bad. Anyway to test this and does anyone have an ecu for sale?

[redlowrey]

Before you condemn the computer, do a voltage drop test first and make sure.

[Wendell11]

Redlowrey where would I find instructions to do that?

[Wendell11]

Ok so I checked all electrical connections and ohmed out parts per manual. Every thing seems to check out within spec. The problem is I am dumping a lot of fuel out of the exhaust through The prop. Motor tries to start but dies quick. Not sure if it is flooding and I'm still not convinced the ecu wasn't damaged when all wires shorted. Any info or advice on where to look.

[redlowrey]

Pull the plugs out and see if they are all wet or only two are wet, if all four are wet, all the injectors are spraying come back on the forum with the results I will give you some voltage drop tests to do.

[Wendell11]

Seems only 2 are wet. And they are really wet.

[redlowrey]

It sounds like a couple of transistor drivers are fried, shorted and the injectors are spraying as soon as you turn the key on. connect up a test light to battery pos .disconnect the injectors, with the key on, probe the ground pin next to the grey wire and if it lights the injector driver is at ground, or there are other wires going to ground from the burnt loom, test the others and the drivers that are good, the test light won't light.

If that is the case I would disconnect the ecu and do an ohm meter test to make sure no other wires are interfere ring with the injector grounds. You being an electrician stick an amp clamp around the injector wire and it will read around 900ma. if it is stuck on with the key on.

For a driver to fry, battery pos would have had to melt into the injector ground wires and when the key was turned to the start position the driver would have copt a dead short

[Wendell11]

Redlowery I will check this evening thank you. I am sure there was a dead short somewhere with everything that melted and not knowing it had melted and trying to start motor.

[Wendell11]

Okay so I hooked my test light to battery positive and checked each gray wire. Light lit on all 4 then with the key off it lit on wire opposite of gray on cyl 1 and 3 no light on 2 or 4 .