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blowning fuse on motor

aristakat

aristakat

Regular Contributor
Okay Guys need some imput,

background
I am motoring 32 miles off shore in 4 ft seas I get 1 mile from site and motor starts to die and then motor completely stop goes dead, no power whats so ever, no hour meter , no key switch nothing.. I find a blown 10 amp fuse replace w only spare 15 amp fuse I have, go back to motoring all worked then all of sudden motor starts surging as before trying to shut down seems like a loose connection on a main wire ? when I get back to dock after 1hr and 30
mintues ride at dock fuse blows again... number 3 fuse on side off motor block anyone know what I should look for and where ???? why is is blowning ? is it a bad wire or loose connection ? number 28,29,30 is fuses box that I am speaking about

http://www.boats.net/parts/search/Honda/Outboard Engine/2002/BF225A2 XA /STARTER CABLE/parts.html
 
The manual says that fuse is for the Alternator (output terminal), Engine oil pressure, Overheat indicator, Power tilt relay, PGM-FI main relay, Tachometer, Trim meter, Warning buzzer.

Basically, it could be any of these items drawing too much current. There could be a wire at the helm shorting/arcing to ground (that wire could be going to the oil pressure/overheat indicator, tach, trim meter or warning buzzer)

Since it did not blow right away and there was running problems, the most likely area is the main relay. It provides the starter, fuel pump and ECM with power. It has some diodes etc inside and there may be some internal low resistance shorts happening that eventually draw enough current to blow the fuse. This fuse first feeds the key switch, which sends it to all those other places. So it is possible that you could have an internal short (caused by corrosion) inside your keyswitch (there are grounds inside the switch).

It is a black/white lead going to the switch from the fuse and a black/yellow lead from the switch to all the other items that I listed above.

This could be a real bear to find. If you have a clamp on DC amp meter, you might be able to isolate the problem area, by finding the ground wire associated with each of the listed items and check for excessive current flow on each one. Measuring the current on the positive lead could also work, but might give you some false readings unless you connect at just the right spot.

If you do not have the repair manual, go to the owner's manual and check out the wiring diagram in the last few pages.

Mike
 
Jamie - do I recall correctly that you have twin 225's? If so, is it possible to unplug the two key switch assemblies, and plug the motor that's blowing the fuses to the other key switch and test that way? If so, that would pinpoint or eliminate a key switch problem.
 
yes twin 2002 honda 225 that sound like the easy check will switch the key switches

thanks if anyone has more imput please share I will share once I switch the switches and see if problem switches motors

thanks for imput
 
Jamie - also if my recollection is correct (my boat is in the water and shop manual not immediately available) but I think there is a rather critical ground wire that comes off the tilt/trim motor, or the relay, to the engine mount to insure a good ground. You might check that.
 
I hope it doesn't come to this and, usually it doesn't but I will give you this now just in case you need it later.

In cases where a single fuse feeds multiple circuits and you can't locate the cause of the fuse blowing, it can become necessary to install "substitute" fuses in each individual circuit. This involves tapping in to each line in the most convenient place you can find and installing a fuse OF A SLIGHTLY LOWER amperage than the circuit calls for. In this case, the circuit is 10a. so a 7.5a SECONDARY fuse in each line should open before the 10a does and help you identify a circuit with a line fault.

And, you don't necessarily need to do this on all branches from the fuse at first. If there are "usual suspects" such as the TRIM/TILT that chawk mentioned or the MAIN RELAY that Mike indicated, you could just do those initially and wait to do the other lines if that yields no immediate results.

In rare cases, this doesn't work as planned and then I have had to revert to "shunting" the primary fuse to keep it from blowing. In other words, hard wiring around the primary so that my secondary fuses provide the protection for each line load by themselves. In this scenario, you should still be able to use a less than specified fuse for each line so that the substitute fuse will RELIABLY fail in a short time and identify the problem for you.

Capt. Jamie, I cringed when I read that you popped in a 15a fuse to replace a 10a. I realize that you were in a pickle and all but you should avoid doing this if at all possible so as not to cause any damage to your wiring or components and compound your problems. NEVER exceed the rated amperage for a fuse if you can at all avoid doing so. Bad ju-ju!

Anyway, I hope you find it without having to go through all of this but sometimes a good back up plan is nice to have.

Good luck.
 
Ordered two new key switches see if that helps they looked like they needed replaced even if they aren't problem. So Thursday they come in and will see if it helps
 
Ok Update replaced both key switches old switch wires were open easyly could of been problem when puilling out found one broke that went to kill switch, New switches were sealed unit so looked much better both switches were like total of $70 had to butt connect one of the plug connectors but have had boat out twice now no issues so after 10yrs I think it was swiches.....
 
Spoke to soon blew 10amp fuse AGAIN today after two or three days of no problems... I was triming motors up so going to take a look at controls to see if short somewhere in trim wires next frustrating thought I had it
 
Look where trim wires come out the bottom of the shift handle and go through the base. A skinned wire touching the base can ground through the control cables back to the engine ground.

Mike
 
will do thanks ran today no issue at all will comment once I check trim wires

hondadude said:
Look where trim wires come out the bottom of the shift handle and go through the base. A skinned wire touching the base can ground through the control cables back to the engine ground.

Mike
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