Main Fuse on Merc 90 2-Stroke Fails Repeatedly

rockstarbob

Cadet
Joined
Mar 3, 2010
Messages
18
Good Morning All! I was able to take the Arima I bought about a month ago on her maiden voyage after getting my 96' merc 90 2-stroke out of the shop from a tune up. Nothing special just a quick outing with the crab pots. Everything was in perfect order and the motor ran fantastic and everything else seemed great.

After reaching the crabbing spot we killed the motor and threw out the pots. You can imagine how I felt when I went to get things going again and the motor would not start. After 20 min of troubleshooting I found that the main 20A fuse back at the engine was blown. Not a huge issue since I could spare one from the box up front. After getting running again we finished the trip but didn't shut down the motor until we got back to harbor. Sure enough that 20A main fuse was blown again. This only happens when under power which is the odd part. I can start and stop it all I want in the driveway with the muffs but after being under power for a while it seems that fuse goes out.

It appears that the fuse box under the cockpit is the original on this 88' Arima SeaChaser. Some googling turned up this little nugget

"If the under-cowling main engine fuse repeatedly blows, the problem is likely in some accessory wiring at the helm or a result of a loose connection creating a short circuit somewhere along the way."
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I am just wondering:
If anyone else has had an experience similar to this and if it could be the fault of that old fuse panel?
Any recommendations on good replacement products? I only have 7 or so accessories needing power at this point.

Thank you!
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,807
It is very likely in the ign accessory wiring. Put an ohmmeter on the purple wire, Ign off, and see if it shorts to ground. It will be connected to ground thru your instruments, but will have a few ohms resistance. If dead short, trace it and troubleshoot looking for the short.
 
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