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Alternator not working merc 165 4cyl

Output of alternater DOES NOT GO THRU THE BREAKER.

DO NOT CONNECT THE ALTERNATOR OUTPUT TO THE BRAKER


HOW MANY TIME MUST I say this......
 
I am going to hook it up exactly just like it was (to the starter). I can't remember the gage of the existing wire but if it looks big enough its just a matter of bolting the new alt on, tighten the belt, attach the lead and fire her up. If it didn't run through the breaker before then it wont be now.
 
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kimcrwbr1 said:
The breaker is to protect the ignition wiring from lighting up in case of a direct short.
Kim, look at most any engine harness/hull harness schematics of this type.
The red button circuit breaker protects the helm power circuit.
Once power has reaced the helm area, further circuit protection may be provided.

The alternator will only produce the the current that is being used such as high amp draw appliances.
Agreed! That and whatever the battery demands.


Keep the ignition on a dedicated circuit
Agreed!

and the house circuit on its own fuse panel. Fuse your house circuit at the battery with a in line fuse usually 50 or 60 amp with a heavy guage wire to the fues block under the dash with a master switch.
This circuit already exists within the engine/hull harness, and it's protection is via the red button circuit breaker.... yes/no?
Click to expand...
 
kimcrwbr1 said:
The breaker is to protect the ignition wiring from lighting up in case of a direct short. The alternator will only produce the the current that is being used such as high amp draw appliances. Keep the ignition on a dedicated circuit and the house circuit on its own fuse panel. Fuse your house circuit at the battery with a in line fuse usually 50 or 60 amp with a heavy guage wire to the fues block under the dash with a master switch. It is also recommended to install a volt meter directly to the battery using the ignition on pos and a good neg (ground). That way you can monitor the charging system real time while the engine is running.
http://www.boatdesign.net/forums/at...g-schematic-diagram-instrumentpanelwiring.jpg
Fuse everything!!
Click to expand...

He has a simple boat.......No "house" or other type of circuitry. His wiring is of the simplest form for a boat. One main/complete circuit for everything.

A volt meter gets connected to the Ignition ON circuit so the meter is only reading when the Key is on. (purple wire in most cases) This is the case for all gages. There power comes from the ignition on circuit. With the exception of the older AMP gage. Which if is installed I would remove it and convert to a volt meter.

If you connect it to the battery or battery connections directly you will kill/drain the battery..........

the schematic you posted is nice and all but they used the wrong color coding for the gages.....the power daisy chain connection for them should have been PURPLE in color. (STANDARD WIRE COLOR) and they should have been more clear on showing it was from the switched ON side of the ignition switch.

See updated image below.
 
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kghost said:
A volt meter gets connected to the Ignition ON circuit so the meter is only reading when the Key is on. (purple wire in most cases)
Yes!

This is the case for all gages. Their power comes from the ignition on circuit. With the exception of the older AMP gage Which if is installed I would remove it and convert to a volt meter.
I would also if an ammeter is installed now.
This would cause the need to remove or circumvent the Ammeter return circuit....... of which makes a loop to/from the ammeter... so to speak.

If you connect it to the battery or battery connections directly you will kill/drain the battery..........
Yep!

Click to expand...
 
kghost said:
He has a simple boat.......No "house" or other type of circuitry. His wiring is of the simplest form for a boat. One main/complete circuit for everything
.........
.
Click to expand...

Yep. Simple wiring. Two batteries connected to a battery switch. There is a positive running to the dash fuse box that isn't fused at the battery. I'm pretty sure it comes off the battery switch though so it can be "turned off" when the boat isn't being used. The alternator circuit isn't protected ether if it doesn't go through that red button breaker if I'm understanding all of this correctly.
 
It worked with the other alternator it should be fine with the new one..

Way to much info here for simply replacing an alternator............................

The red/positive wire is what supplies the ignition switch power and as the pic shows for your switches for blower, bilge pump and lights....

The big battery switch is there as a way to have two batteries so if one dies you can switch to the other (with the ignition OFF) otherwise if you switch it while it is running it will blow the diodes in the alternator.........


Also it allows to shut off or disconnect the batteries from everything incase you have an accessory that draws power when the boat is off.....or just to isolate the batteries from everything.
 
kghost said:
The big battery switch is there as a way to have two batteries so if one dies you can switch to the other (with the ignition OFF) otherwise if you switch it while it is running it will blow the diodes in the alternator.........

Also it allows to shut off or disconnect the batteries from everything incase you have an accessory that draws power when the boat is off.....or just to isolate the batteries from everything.
Click to expand...

There hasn't been an MBSS made for years that wasn't "make-before-break", which means that you can switch between battery bank #1 and battery bank 2# while the engine is running!

Just don't switch to or through the "OFF" position!


.
 
His Boat is a old one.........who knows when the battery switch was installed..........better safe than replacing the alternator again.........
 
kghost said:
His Boat is a old one.........who knows when the battery switch was installed..........better safe than replacing the alternator again.........
Click to expand...

I agree...... better safe than sorry!

Simple check:
select batt #1
turn on a 12 vdc item
slowly switch to ALL or BOTH
slowly switch to batt #2

If you did not lose power, then the MBSS is "make-before-break"!

If you lost power momentarily, then the MBSS is NOT "make-before-break"!


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