Adding an ammeter (or two) to the dash

Deep Blue

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#1
Has anyone ever done this? I have a 2003 and other than a tiny value displayed on one of the Yamaha gauges there's no way to sense the state of the electrical system when idling, running at high speed, raising the anchor, etc.
 

Doc Stressor

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#2
I would not recommend using an ammeter with outboard engines. There is a history of them damaging rectifiers, at least on older engines.

All you need is a voltmeter to assess the state of your electrical system. Most MFD/Fishfinders have one already built in. You can address that display under setup options.
 

SkunkBoat

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#3
While I don't see a real need for a permanent ammeter on the dash, there are clamp on ammeters or clamp-on ammeter accessories to digital voltmeters.
Available at Home Depot or online..

that could help determine your actual current draw thru the HOUSE feed with everything on and/or the current draw of your windlass.
That would help you determine if you need heavier gauge wire.

Actually, I should do that! With so much added electronics I think the feed to the dash is at its limit.
could probably replace the 10 gauge feed up to the electronics box with its own home run to a breaker and the battery

The clamp on meter can be moved around to check different things. Much more practical.
 

Deep Blue

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#5
I would not recommend using an ammeter with outboard engines. There is a history of them damaging rectifiers, at least on older engines.

All you need is a voltmeter to assess the state of your electrical system. Most MFD/Fishfinders have one already built in. You can address that display under setup options.
Unfortunately the 2003 Yamaha engines don't output that data via NMEA, it wasn't until (I think) 2004 or 2005.
 

wspitler

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#7
Remember that an ammeter only measures current through a specific wire. In powering a load or loads, the batteries and the alternators both provide a voltage potential to produce a current based on the circuit resistance (load). They share the load depending on how large the load is. Depending on where you put the ammeter coil (sensor) you'll need to figure out what is providing the current, be it batteries and/or alternators. The alternators have a rating that varies with RPM and the batteries are rated and vary with temperature. age. etc. Quite a few variables to consider. You would need an ammeter that tells how much each source provides to really be meaningful. A voltmeter would give a better indication of system health. Newer voltage regulators are smart and don't always charge at the same voltage. Above 15 VDC is worrisome and below 12.4 or so is also of concern. If your voltage isn't dropping during long trolling periods and your batteries are above 12 VDC without engines running and normal loads, I'd not worry about it.
 

SkunkBoat

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#8
hahaha... look on Amazon for DC clamp on ammeter...Not all clamp meters read DC current so you have to pay attention to what your buying...
you can find a meter for $9 ---shipped from China... makes it hard to figure out what is a valid price for a decent meter. FLUKE makes quality stuff but it aint cheap.

Ive got a Fluke DMM for serious stuff and a few FREE Harbor Freight giveaways laying around for if the Fluke is in the boat.
The cheap DMMs usually have one function that doesn't:rolleyes: and the leads are such crap that you might be troubleshooting bad meter leads...

I don't have a clamp on DC current meter so Im going to research it a bit and try and find a somewhat cheap usable one.
Reading current is not a common thing troubleshooting 12V DC circuits because it used to be a real pain to break into a circuit to measure current.
A reasonably priced clamp DC ammeter actually makes it a useful troubleshooting step.
 

Fishtales

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#9
X2 on the Fluke. I have the 87 when needed and a cheap-0 Radio Shack from the 1980s as a back up.
clamp on is a good idea. I don't see the value/risk tradeoff putting them in the dash, just me.
 

seasick

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#10
I have to agree with wspliter. A current probe like a clamp on ammeter will only tell you what is going on in that specific conductor . To get a real understanding of the entire picture you would need to have measurements at the output of the alternator, the hot side of the battery (batteries) and the common feed for accessories. You would also need to understand that the readings at the battery feed could be positive or negative indication which direction current flow is. In fact a reading of zero is not a bad thing, it just means that the net draw from the batteries is zero.
Using a voltage reading as a general indicator of electrical health is far easier and after monitoring actual voltages over time and under different circumstances, you get to know when things are not quite right