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Crossed battery cables

C

cd_frazer

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Dumb Me! Crossed the battery c

Dumb Me! Crossed the battery cables. I have a 5.0 260hp MPI Now my ignition and all of my guages do not work. I do have power going to my starter. I cannot find any inline fuses. I also tried the 50amp circuit breaker on top of the engine.Any ideas?
 
"For starters, i think you can

"For starters, i think you can safely scrap anything that has electronics in it, as you not only created a short condition, but also you had voltage on pins/lines where it wasn't supposed to be. If you have mercathode it's prob shot too. Di you try and crank the motor with the batt crossed? The base engine electrical system may be ok but i'd suspect alot/all your efi stuff is toast as prob is the engine computer. what's the status of the boat now, what does/doesn't it do?

--chris"
 
"Hi Chris! I did not try and s

"Hi Chris! I did not try and start the boat. My trim, and automatic bilge work. I located three small 20amp fuses on the top of the engine they did not blow. The fuse in the back of the radio did not blow. Nor did the inline fuse coming from the positive lead on the battery blow. I was told it might be the 50amp fuse on the engine. Not sure how to check.
Clayne"
 
"Seems to be that the first th

"Seems to be that the first thing to do is start at the beginning; check voltage between the various terminals at your key, with the key in the OFF position and the key in the ON position. The key in the ON position should be aupplying power to your ignition wire, which is usually purple...refer to your boat's wiring schematic. This purple wire usually supplies power to your boats instrumentation, and more importantly, to your boat's ignition components in the engine room. It sounds like your purple wire is dead for whatever reason...check again under the dash, tracking that wire from the "I" terminal on the key, and see if you can find an inline fuse.

Can you be more specific on your engine/boat? What year?

Also, have your battery load tested at your nearest Autozone. That way, you are sure of your power source."
 
"Alternator may be fried; star

"Alternator may be fried; starter also cooked depending on how long the cables were switched.
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"Thanks Guys! I spoke with Mer

"Thanks Guys! I spoke with Mercrusier, they said I more than likely just blew the 90amp fuse at the starter ($20 part). Will try it and let you know. Daniel,my boat is a 2002 Harris Kayot 20V 5.0 MPI 260hp. Maybe my mistake can help someone else!
"
 
"I am praying I am wrong, but

"I am praying I am wrong, but its almost a certainty that your ECM is fried. They don't like reversed polarity at all.

As Daniel has said, you first need to find out if you have power to the purple engine harness wire. This comes in on pin #5.

If not, trace it back to the key switch and see where you are losing power.

The red/pur wire at the 50 amp circuit breaker should be hot at all times. If not, and it won't reset, it may be fried. This wire supplies power to the B terminal on the key switch. Check if that is hot.

Let us know what you find from this and we can take you to the next steps. There is no sense in further speculation until we know what's up with your main power.

Rod"
 
"I am having a hard time belie

"I am having a hard time believing there are no safety features on a boat to prevent damaging the electrical system by reverse polarization. Especially in the last 15 or 20 years. All cars have them. Boat maintenance usually requires the removal of the battery often for various reasons and the chance of this happening is greater in boats than in cars. I did the same thing on my 1994 Isuzu Rodeo and the only thing that happened was I blew a 60AMP main fuse. $3 later everything worked fine and was good to go, no problems at all. I would try replacing the 90AMP fuse that mercruiser told you about first and go from there. In a perfect world that should be the main fuse and there should be no damage past that."
 
"Problem Solved<[img]"http://w

"Problem Solved
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It was the 90amp fuse ($20) connected to the starter. Thats why they put it there. Common mistake. Most boats have them. Mercrusier has a Service Rep. available via internet (you need to know your engine serial #) or via phone. I made one call and was connected to him. Thanks to all who offered advise or suggestions.
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"Thanks guys! The website is:

"Thanks guys! The website is: mercurymarine.com click on contact us. MerCrusier is in Stillwater,OK 405-743-6566. Listen to the prompts.
You can also fax them. # is on website."
 
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