Eliminating the ammeter

[Chris Simenstad]

A few years ago I replaced the original stock 35 amp Motorola with the 55 amp API alternator. The voltage at the batteries seemed to inch up very slowly when recharging. I assumed that the Motorola was worn.

For the most part, the API doesn't charge any faster. After a few hours of motoring it gets up to about 13.5 volts, so when I am on a two week cruise, the batteries are only partially charged.

Looking at the wiring, I see that there is an orange wire that runs from the alternator back to the ammeter in the cockpit, then back to the starter and battery switch. I assume that I am getting significant voltage drop.

I'd like to:

- eliminate the anmeter, and add a tach in its place. (The other gauges are oil pressure and operating temp, and all three share wires)
- Add a voltmeter near the switch panel in the cabin.

How do I remove the anmeter without affecting the other gauges? And without it, how should I run the wire from the alternator? Just go straight from the alternator to the starter?

-Chris

[joe_db]

A few years ago I replaced the original stock 35 amp Motorola with the 55 amp API alternator. The voltage at the batteries seemed to inch up very slowly when recharging. I assumed that the Motorola was worn.

For the most part, the API doesn't charge any faster. After a few hours of motoring it gets up to about 13.5 volts, so when I am on a two week cruise, the batteries are only partially charged.

Looking at the wiring, I see that there is an orange wire that runs from the alternator back to the ammeter in the cockpit, then back to the starter and battery switch. I assume that I am getting significant voltage drop.

I'd like to:

- eliminate the anmeter, and add a tach in its place. (The other gauges are oil pressure and operating temp, and all three share wires)
- Add a voltmeter near the switch panel in the cabin.

How do I remove the anmeter without affecting the other gauges? And without it, how should I run the wire from the alternator? Just go straight from the alternator to the starter?

-Chris

This is very much worth doing and there are likely 50 threads on it.
You can try this thread:

http://www.moyermarineforum.com/forums/showthread.php?t=9525&highlight=voltmeter

that contains this picture

[toddster]

As soon as I ran the bypass wire (I think mine is about 8 inches of 4 gauge) there was a huge change. When the alternator kicks in, the voltmeter jumps right up. I don't think the ammeter was working at all.

Re: "Removing the ammeter without affecting the other gauges." The way my control panel came, all the gauges were daisy-chained together in a nasty snarl of wires - many of which terminated at the ammeter, as it was "the source" for panel lights, blower, hour meter, etc. The simple - but probably not correct - thing to do would be just rearrange the daisy chain and jump all those extra 12V+ wires (if present) to the "battery" terminal. Thus maintaining the original rats nest arrangement. I did this as a "temporary measure."

But recently, I built a new control panel and complete new wiring harness for the engine, using a fuse block and terminal buses for "ground" "always 12V+" and "switched 12V+." Plus another terminal strip for all the instrument lights. It was a lot of work and a whole lot of wiring connectors. But now any component can be removed (or tested) by disconnecting its terminal screws, without affecting the rest.

[amizerin]

This is very much worth doing and there are likely 50 threads on it.
You can try this thread:

http://www.moyermarineforum.com/forums/showthread.php?t=9525&highlight=voltmeter

that contains this picture

Have the same problem but the link doesn't work

[Administrator]

The link mentioned in Joe's very helpful post has been fixed.

Bill

[svclevergirl]

Oh my. Currently (no pun intended) I am analyzing / upgrading / retrofitting the electrical system of my Pearson 28-1. This is EXACTLY what I needed! Thank you guys!

John

[lat 64]

I like ammeters.
Im building a whole new panel for the ol' boat.
For the reason stated by the OP I don't like the idea of series ammeters, so I'm putting a shunt ammeter in mine. I put the shunt(50-Milivolt) in the negative circuit just after the negative buss on it's return to the battery.
I'm not sure if this setup will show all the potential leaks to ground, but it's more to help guide me in power management. Possibly some improved safety too, as any contact with the big shunt post to ground, will not short the curent. Nothing like dropping a wrench on a terminal post to wake you up!

[ndutton]

I removed my cockpit panel ammeter in favor of a volt meter but added a digital ammeter inside the cabin that reads the alternator output only (very interesting!). The sensor is a Gauss loop on the alternator output wire.

[joe_db]

I like ammeters.
Im building a whole new panel for the ol' boat.
For the reason stated by the OP I don't like the idea of series ammeters, so I'm putting a shunt ammeter in mine. I put the shunt(50-Milivolt) in the negative circuit just after the negative buss on it's return to the battery.
I'm not sure if this setup will show all the potential leaks to ground, but it's more to help guide me in power management. Possibly some improved safety too, as any contact with the big shunt post to ground, will not short the curent. Nothing like dropping a wrench on a terminal post to wake you up!

Shunts usually are on the negative side. That way you don't need to fuse the wires from the shunt.

The ammeter in the photo runs from a shunt.