eliminate ammeter question

[msmith10]

I'm replacing my worn out Motorola alternator with the 55 amp API from Moyer. While doing this I thought I might as well remove the ammeter (I'll put it in the engine compartment and replace it with a voltmeter at the instrument panel).

I understand wiring from the alternator output to the + terminal on the starter solenoid, but I have 2 questions:
1. What happens to the orange wire going to the battery terminal on the igntion switch? If I remove the orange wire won't it cut off my main distribution panel?
Does current need to be supplied to the battery terminal on the ignition switch?
2. Removing the orange wire will cut off my main distribution panel, right? Where's the best place from which to feed the main distribution panel? Should I just run a properly sized wire from the battery switch "out" to the panel?

[ndutton]

Originally Posted by msmith10

1. What happens to the orange wire going to the battery terminal on the ignition switch? If I remove the orange wire won't it cut off my main distribution panel? Does current need to be supplied to the battery terminal on the ignition switch?

Orange wire is removed or abandoned. I prefer removal. Depending on the distribution panel's source, it may lose power. The ignition switch gets battery + power from the red wire. See the attachment in post #1 of this thread.

2. Removing the orange wire will cut off my main distribution panel, right? Where's the best place from which to feed the main distribution panel? Should I just run a properly sized wire from the battery switch "out" to the panel?

Yes.
Battery switch post also known as 'common'.

[msmith10]

That makes sense, Neil. Thanks.

[BunnyPlanet169]

Mark - why the interest in removing the ammeter? I find mine useful.

I have the 55 amp alternator also, and a 40A ammeter. Even with the batteries combined I never see more than about 25 - 30A, and then only briefly - the batteries acceptance rate is much lower. That's with 3 group 24s, YMMV. The extra capacity on the alternator is just breathing room for a lower % duty and longer life.

[ndutton]

Originally Posted by BunnyPlanet169

Mark - why the interest in removing the ammeter? I find mine useful.

It's not so much the ammeter as it is the lengthy wire run to and from and the resultant charging voltage loss due to voltage drop.

Three ways to mitigate voltage drop are:

1. Bigger wire
2. Shorter length
3. Less amperage

Eliminating the lengthy wire run addresses #2.

[BunnyPlanet169]

Fair enough. I went with #1. It's interesting to see all the different needs and solutions.

[romantic comedy]

You can also use an ammeter with a shunt.

[ndutton]

Originally Posted by romantic comedy

You can also use an ammeter with a shunt.

True. A shunt is typically located near the engine therefore utilizing the #2 strategy above (greatly reduced circuit length). Note however, the vast majority of factory ammeters are direct connect - not shunt type.

[msmith10]

Reducing voltage drop and simplifying wiring layout are my goals. I do have a new ammeter with shunt to install and I will leave this in the engine compartment with a voltmeter at the instrument panel.

[Dave Neptune]

Mark, last year I did the same. I did a rewire and new panel. At that time I swapped a volt for amps in the cockpit and installed a VDO shunt ammeter on my "engine" panel below. Due to the layout of my boat I eliminated around 30 feet of wire between the alt and the batteries~the run is now less that 3 feet! Made a big improvement all the way around!! Well worth the effort!

Dave Neptune

[romantic comedy]

There are also very cheap inductive ammeters on ebay, I think.

Someone posted a link for very cheap volt meters and ammeters here.

[joe_db]

Originally Posted by romantic comedy

There are also very cheap inductive ammeters on ebay, I think.

Someone posted a link for very cheap volt meters and ammeters here.

http://stores.ebay.com/Elite-element?_rdc=1

http://stores.ebay.com/ColdfusionX-Electronics?_rdc=1

[hanleyclifford]

I've got one of these for cheap; send me a PM: http://www.defender.com/product.jsp?...0009&id=341907

[BunnyPlanet169]

500A!?! What was that intended for Hanley - monitoring the on-board welding system?

[hanleyclifford]

Originally Posted by BunnyPlanet169

500A!?! What was that intended for Hanley - monitoring the on-board welding system?

Don't you like to watch your starter motor drinking?

[joe_db]

My A4 draws about 130 amps at startup.

Originally Posted by hanleyclifford

Don't you like to watch your starter motor drinking?

[BunnyPlanet169]

My ammeter is off the alternator output and I use it for basic charging health. I looked at battery monitoring (in and out) with additional shunts and displays and decided it was too $ophisticated for my present use. Very cool, though.

Of course, with in-cockpit welding capability, I might need more metering.