[TomFasig]

I have a Mariah Talari 201 that I recently purchased and have been trying to work out all of the mechanical/electrical problems. The first problem that I found was a bad fuel pump. I replaced it and then found that the engine would not shut off when the key was turned off. It appeared as though someone had changed the alternator, so I checked the wiring out and found that the only wire that was installed in the correct location, was the orange wire. It's hard to get that one wrong because of the size of the lug. I got the wiring info off of the Mercruiser Maintenance manual, but there is one wire that is purple/yellow that the manual says is a "Ballast Bypass", but it doesn't tell me which lug to put it on. I also don't know what it is for. Is there anyone out there that can guide me in the right direction? Also, I'm only showing around 11.8 volts on the voltmeter, so I'm not too sure the alternator didn't get fried when wired wrong. Any advice will be greatly appreciated. Thanks. Tom

[ColoradoDiablo]

Tom check out the Thunderbolt V section here.

Alt Wiring

Looks like that wire goes to the electric choke.

As for low voltage , test the alternator to make sure it is charging.
If so , loose belt maybe , or bad connection in the charge system.

[TomFasig]

Thanks Larry. All that I could find on the Thunderbolt V info was the purple/white wire goes to the choke. This is a purple/yellow wire and the Mercruiser color code for wires says it is for a ballast bypass. On another subject, is there a fuse/circuit breaker panel on my boat and if so, where wouild it be located. I've looked every where that I can think, to look, and I can't find one anywhere. Thanks, Tom

[ColoradoDiablo]

Look under the dash on the starboard side(Steering wheel). That is almost always where the fuse box is.
They are really stuck up under there Tom. Might have to remove the kick panel to access it.
Just remembered........some are kinda by the shifter also. But , I think that is on Jubilee boats.

[husker_fan]

In my experience the ballast bypass is the r terminal on the starter. On mine it runs the fuel pump and ignition when the switch is in the start position. If this wire is on the wrong terminal the engine won't shut off either. I had my solenoid take a dump just recently so this is pretty fresh in my mind. Im even thinking the wire was yellow with a purple tracer too but I'd have to look to confirm.

Sent from my SCH-I535 using Xparent ICS Tapatalk 2

[ColoradoDiablo]

The wiring diagram is in my post above.

[TomFasig]

Many thanks for all of the valuable infomation. I got the alternator wired properly, and now the engine shuts off, as it should. The problem was, that the battery hot and the switched hot were on the wrong terminals. Also, I found the fuse panel. It is a bear to get to. I'm not sure this old body can get in that kind of a position, to be able to check and/or change fuses. I haven't been able to find the horn, yet. I will just follow the wire from the fuse panel and maybe there will be a horn on the end of the wire. Ha Ha !!!! Again, thanks for your help. Tom

[ColoradoDiablo]

I'm with ya Tom LOL. I am planning to move the fusebox on my Diablo to a little more convenient location in the near future.
Glad you got it straightened out , and Happy Boating!!

[mikeyt]

Originally Posted by TomFasig

Many thanks for all of the valuable infomation. I got the alternator wired properly, and now the engine shuts off, as it should. The problem was, that the battery hot and the switched hot were on the wrong terminals. Also, I found the fuse panel. It is a bear to get to. I'm not sure this old body can get in that kind of a position, to be able to check and/or change fuses. I haven't been able to find the horn, yet. I will just follow the wire from the fuse panel and maybe there will be a horn on the end of the wire. Ha Ha !!!! Again, thanks for your help. Tom

Hi Tom,

My horn is mounted right beside (to the left of) the fuse block up underneath the dash.