Logo
FULL SITE MENU

Please Help! Mercruiser 1998 3.0 Alpha One

J

jpx8080

New member
OK... Hello everyone,

Here is the issue: I have a Mercruiser 3.0 with an Alpha One outdrive on a 1998 Stingray 190RS. I can run WOT with out any issues but intermittently when I bring the throttle back to neutral I blow the 10A ignition fuse. I went through the whole adjustment for the shift cable and interrupt switch and all seemed well. (I thought that it was the problem initially but now I'm not so sure).

I was checking all of the wiring today and when I was looking through the schematics I noticed that the purple wire seems to be the main wire on the engine that keeps the boat running.

I also noticed that my purple wire was short to ground. Maybe this is why it is blowing the fuse? I started disconnecting everything that is connected to purple to try to isolate the ground and it seems that the only thing to disconnect the purple from ground is removing it from the electric choke.

Now I am not sure but is it normal for the purple to have a short reading to ground with the choke connected? I'm at a loss here. I only have 189 hours on the boat and this is the first real issue that I've had. I don't want to take it to a marina and pay for a bunch of experiments! I'm an electronics tech for the Coast Guard so I know my way around wiring if any of you would be able to help me figure out why this fuse is blowing...

Thanks in advance,

Paul
 
Re: Please Help! Mercruiser 3.0 Alpha One

Start with the basics on the RUN circut which is the purple wire in your boat.

The purple wire gets its power from the KEY switch, When the key is in the ON position It goes to all the guages in the dash. It also goes to the motor thru the harness, at the motor it goes to the coil + , the choke and the Altinator thats it!!

The fuse you speak of, what color wire is going to it? If it is not purple then that is not your problem,


Can you post a copy of the schematic? Point out where the fuse is?

When shifting from full throttle from either reverse or forward the only switches that are activated are the shift interuptor and the neutral safety switch.

The nuetral safety switch ( normally closed when in neutral) if open will not allow the motor to turn over when the control handle is in for or rev before starting, the shift interuptor will short the NEGATIVE side of the coil to ground when activated ( normally open switch) and it should only happen for a split second, if it happens longer then the motor should shut down, NO fuse to blow.

Re-evaluate your wiring and colors and report back with more specific info, Exactly what wire is going to fuse and from where and to where.....

ALso you can disconnect the purple wire at the choke and everything will work as it is suppose to except the choke, so maybe do it when warm. If the choke is shorted to ground I would suspect it would not be working and you would have running issues as well.......
 
Re: Please Help! Mercruiser 3.0 Alpha One

Attached is a wiring diagram for the basic dash layout, disregard the newer style shift control, the wiring is still the same......
 
Re: Please Help! Mercruiser 3.0 Alpha One

as mentioned the fuse to the choke heater is too small. make sure you have the correct fuse and type. the choke draws alot of amps.
 
Back
Top