2003 Yamaha 200HP Four Stroke - Keep blowing 10A fuse to fuel pump,etc

[legalangler]

Hey folks, I've got a 2003 F200TXRB with about 250 hours and it died on the water for me a couple months ago. The 10 amp fuse that handles the fuel pump, Injectors, coil packs and idle control valve. Have ruled out fuel pump and no grounding errors. My mechanic is worried that it may need a new CDI/ECM which is pricey. We have been dealing with old fuel related issues from before I bought the boat., clogged injectors, filters, etc., but had pretty much resolved that when the idle started misbehaving. Idle was running high in N and would not kick down. Sounds like that could be IAC/ISC but my questions are:
Could a bad IAC valve cause the fuse to keep blowing? Anything else to consider before replacing CDI/ECM? Is there a way to check the CDI/ECM before actually replacing it if the engine will not start because of the continually blown fuses?

Thanks for your thoughts.

 

[99yam40]

I would think a clamp on DC ampmeter would help find what was and what did not pull too many amps

 

[boscoe99]

The fuse from the battery to the main relay is a 20 amp fuse. Use of a 10 amp fuse can be problematic.

 

[legalangler]

Thanks for the responses. It seems that amps pulled for each component on that fuse are normal.

 

[tommarvin]

Yes, you should clean the fuel system especially if its been dirty/sitting.
We had this problem old fuel, clean the fuel injectors, install new fuel filter, its on you tube.
Clean the screen in front of the high pressure fuel pump,and VST.tank,.on motor fuel filter,and the fuel water separator buy a new one or dump out the old filterin a glass container look for garbage and water in the fuel fill it up with fresh fuel and spin it back on.
Yes you can test the CDI/ECM with a multimeter or a i think its a DvA better test.
The fuses blowing sounds like a dead short, check every inch of wire and find it.first before you buy anything
Our motors would not idle down because of a dirty fuel system, now our twins purr at 550-600rpm you cant even hear them you have to look for the teletale to know if there running.