Eletctric problem with fuse

seakingbob

Petty Officer 2nd Class
Joined
Jul 10, 2008
Messages
170
I am looking at buying a Dusky 21' boat with a 175 Evinrude.The guy told me that it blows the fuse once its starts and that it will keep running till you turn it off.Once you turn it off you have the put a new fuse in it to start it .Does anyone know what could be the problem and do you think it's worth to buy it.The price is pretty good,but I can't spend alot of money to fix it.
Thanks for any and all replies
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Eletctric problem with fuse

it could be as simple as corroded dirty connection. or a bad solenoid, short in starting circuit.
90% of starter problems are bad connections. remove and clean both ends of the battery cables, so that they are shiney, also the cable from the solenoid to starter. check for nicks in the cables. and make sure the connectors are on the wire good. the cable tend to corrode from the inside out, if nicked, corroded wires, and connections, heat up and cause resistance to the follow of electricity, thus the starter doesn't get enough. you can also take jumper cable pos battery post to large post on starter. with a good connection, the engine should spin. then if the starter is good clean everything and retest. then trouble shoot solenoid. starters can be rebuit at a starter/alternator shop, much cheaper than a new one.

also have the battery load tested at the auto parts store, free, i've had new batteries go bad
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,109
Re: Eletctric problem with fuse

Bob, You did not mention the year of the motor, however, I had an identical problem on my '98 Johnny 150HP. it turned out to be the purple wire was shorted to ground under the dash where it connected to the first guage. The purple wire is the switched +12V used to run the gauges, warning system and the voltage regulator. When the ign key hits the run position, +12V is applied to the purple wire and it blows the 20A fise. The purple wire somehow melted the insulation off of itself and the ground (black) wire next to it, causing the short.

If this is your problem, it can take some time to find the shorted wires, but the fix is easy. I would look first at the engine wiring harness where it plugs into the boat wiring harness, and second under the dash.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Eletctric problem with fuse

Its apparent you have a short in your system somewhere, the trouble will be finding it. I have located similar shorts to this with an analog (needle) type ohmmeter. Set the meter to HIGH ohms scale. Remove the fuse, and insert one of the probes into the connector, the other probe to ground. The meter should have minimal reading, but not full scale. If it does, try the meter on low ohms after resetting the meter needle.

Now just start tugging and wiggling wires until the meter spikes. When it does, you have found your short. This is a fairly good method since some of the cracks or breaks in the wire insulation can be hard to see.

This is obviously much easier with a helper. I use my wife, but I dont loan her out :)
 

seakingbob

Petty Officer 2nd Class
Joined
Jul 10, 2008
Messages
170
Re: Eletctric problem with fuse

Thanks Guys,I'm definitely thinking about make a offer on the boat.Seems like it may be not to bad to fix.I don't know the year of the motor,but the boat is a 1981.Looks like it's in pretty good shape from the pics.Just a 2 hour ride to look at it.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: Eletctric problem with fuse

If it is a 2 hour ride, I would bring my tool box with me to check out the usual stuff before giving a down payment. Dont want to get caught with your pants down :)

Good luck, hope she turns out well for ya
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: Eletctric problem with fuse

Don't know what is causing your problem but I replaced all my fuses in the motor with marine grade breakers, way easier to just push the button back in than to keep replacing fuses, especialy when you have an unknown problem and may go through a bunch of fuses finding the problem.
 
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