20 amp engine fuse blowing

[TMS4659]

The 20 amp fuse under the engine cowl blows after i crank the engine. I replaced the harness from the main engine cable, but had a TAN wire and a BROWN w/ WHITE strip that had nothing to match to. Are these just 2 more groundss?

 

[Barnacle_Bill]

Re: 20 amp engine fuse blowing

It would help to know what motor you are working on. They are most likely NOT grounds.

 

[TMS4659]

Re: 20 amp engine fuse blowing

the motor im working on is a 2002 Basstracker By Mercury Marine. its a 2-stroke ELPTO, 3 cylinders, 50 hp

 

[Silvertip]

Re: 20 amp engine fuse blowing

Did this problem surface after you did some electrical work on the boat/engine or did it "just happen". With the key OFF, replace the fuse. Now turn the key to RUN (not START). If the fuse blows, you have a problem in the ACCESSORY side of the system. That would be anything connected to the "A" terminal on the ignition switch. If the fuse does not blow in the RUN position but blows when the key is turned to START, you have an engine wiring issue. Start disconnecting things until you find the circuit causing the problem. Disconnected wires don't cause fuses to blow. Shorted circuits do. The tan wire is very likely the temp sender circuit. Don't know what the other one is. Disconnect the power trim system and retest.

 

[TMS4659]

Re: 20 amp engine fuse blowing

SOO the fuse blows while in the RUN position. I only have two wires ruynning from the A pin on the ignition switch. One is purple and runs to the gauges. The other is also purple BUT when i trace it backwards it is originally a TAN w/ BLUE stripe from the motor wiring harness. The tan w/ blue runs into a small white round circuit of some sort and a purple wire is comeing out the other side. This is the second purple wire attached to the A pin.

Any idea which pin to attach this wire??

Thanks for all your help!!!

 

[Silvertip]

Re: 20 amp engine fuse blowing

The next step is to disconnect on of the two wires on the "A" terminal and repeat the test. If the fuse holds - you found the circuit. If not, replace the wire and disconnect the other. If the fuse now holds, you found the problem. If not, I'm out of suggestions.

 

[TMS4659]

Re: 20 amp engine fuse blowing

I took both of the Wires off the A terminal, and the engine started succesfully!!! the one cluster of purple wires goes to the gauges so i know this is supposed to be connected to "A" terminal but could there be a short within the gauge cluster??

Im pretty sure the TAN with BLUE stripe is connected to an ALARM then runs to the "A" terminal. Is this a temperature alarm, or oil alarm or something?

 

[Silvertip]

Re: 20 amp engine fuse blowing

The alarm serves both purposes (oil and overheat). By disconnecting both you still don't know which one is the problem. Connect just one of the two. If the fuse holds, the problem is in the other circuit.