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BF90D - Throttling Up - Dies

M

mgoodling

New member
Hey all. Need quick help here. Visiting my in laws in Florida this week. But, father in law hooked up all wires on the positive terminal to the battery......smoke from engine. Unhooked (within a minute or so), but now have issues. Looking for a few quick hitters to look at.
I'm fairly knowledgeable regarding engines and outboards. But, need some feedback.

Problem, since messing up the wires, after about 1/2 throttle (18 mph) the engine dies. Back off throttle, runs fine again. Starts and idles fine. Seems to only struggle with a decent load on the engine.

Also, May or may not be related but the gauges on the dash are hit and miss. Intermittently working.

Thoughts?

Stranded in Okeechobee.
 
Hi,
Sounds to me as if he might have applied battery positive to a ground wire maybe???

Everything needs a ground
...TPS...MAP....fuel pump...gauges..etc..

If a grounding point for one or more of those items was "compromised" during the smoke event, that might explain the symptoms he's seeing.

Just guessing though.

Good luck.
 
Thanks man. Me, being impatient me, dove in. Found the melted wire and source of smoke. Its the main wiring harness before it reaches the ECU. That said, I've found basically one wire that was melted, it was bare copper, and the melted plastic housing was a mess. I separated the wires. I think the other wires are still intact. I jumped with gator clamps the damaged wire, and it fired up. Test running tomorrow with all functionality. Fingers crossed. I still think the ECU is jacked......we'll know soon enough.

I did start it and tested the alternator, and it's charging fine.

More to come.......I'll keep you all posted
.
Stranded in Okeechobee.
 
This is very odd, usually the only thing that happens when polarity is reversed is the 100 amp fuse blows, full protection. You must have some non factory wiring in your motor
 
Not sure if it's 100% factory or not. I can tell you that the wiring harness certainly appears factory. Now, what I cannot confirm is battery to motor wiring. But, it definitely did melt and burn as noted above. Is the fuse location between the battery and motor? Just curious.
 
Fuse is in a small black box top rear starboard side of the power head. If you have melted wires then the power supply is definitely incorrect. All power should go through the 100amp fuse to efi system.
 
Yea man. I hear ya, makes sense. I'll check it in the morning. I'll keep posting. Might (obviously) need to correct to prevent future snafus.
 
Merry Christmas. Ok. Another update.
Big 70A fuse was fine. Didn't blow. Check the other fuses in the fuse box, no issues, all are good. Since I put the gator clamps on the wire that was fried/melted, engine is running normal. Powers up, top end.....no issues.
Now, here's the next dilemma. The console gauges are intermittently working, and the last trip or so, haven't worked at all. Speedometer, voltmeter, tilt/trim/ and fuel gauge. Also, not sure about the temp alarm and oil idiot lights. But they don't light up when turn the key. The navigation lights are also dead.
Would the ECU have anything to do with this?
 
So, started back tracing wires from console (acc., nav, etc). I found that the power and ground wires are fed to the battery box. I also found where the positive wire connects to the battery, there is, what appears to be, a water proof fuse box, inline with the positive wire. Under the cap, is nothing, but you can clearly see that something should be, or could be plugged into it,very much like a plug in fuse. If this for a fuse, any suggestions on the amperage?
 
So, started back tracing wires from console (acc., nav, etc). I found that the power and ground wires are fed to the battery box. I also found where the positive wire connects to the battery, there is, what appears to be, a water proof fuse box, inline with the positive wire. Under the cap, is nothing, but you can clearly see that something should be, or could be plugged into it,very much like a plug in fuse. If this for a fuse, any suggestions on the amperage?
 
I jumped what was suspected to be a fuse box, and that got power to everything. Now, if I only knew what size fuse to use or just simply bypass?
 
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