Ammeter Wiring

[daveinrenton]

Don,

I noticed you sharing wiring diagrams of simple systems connected to the A-4and am wondering if you have an ammeter wiring diagram. My meter, since I put it in, has never wavered between + and -. That cannot be right and I do hear the motor lug down occasionally when the alternator activates. Since it would be good to verify that the batteries are actually charging from the alternator and when, I need to make sure I did not goof on this installation.

I do have a voltage gauge showing the condition of the batteries that works fine but it is inside by the battery switch and so not informative when I am on deck.

Anything you have would be a help. Don, I just noticed the related thread with Baltimore. Is the diagram shown in one of his notes what I need? Kinda looks like it.

Dave

[Don Moyer]

Dave,

I don't have any other schematic that would alter the information already presented in the schematic posted in the electrical section of the Community Forum (presumably the one to which you're referring). If this is the way your ammeter is connected and it still doesn't show any indication while you have other credible indications that the alternator is working, the ammeter is most likely defective.

Many people today are converting to a voltmeter to monitor alternator performance. The benefit of this approach is that the charging circuit does not have to be run all the way to the cockpit just to go through the ammeter and then back to the big battery cable on the starter solenoid. As long as a voltmeter located in the cockpit reflects the biased voltage of the alternator (13.4 for the original Motorola and 14.2 for most other aftermarket units), the alternator can be assumed to be working OK.

With a voltmeter in the cockpit to monitor alternator performance, the output of the alternator can be connected directly to the big battery cable on the starter solenoid (a distance of about one foot).

Don

[daveinrenton]

Good advice. Thanks.

[Baltimore Sailor]

I'd like to verify the wiring when removing the ammeter from the circuit. In your DC wiring schematic, you show the orange wire from the alternator going to the ammeter, thence to the BATT post on the ignition key. Then the red wire from BATT goes down to the large terminal on the starter where the lead from the battery switch connects.

If you take the ammeter out of the circuit and take the orange wire from the alternator directly to the large terminal, do you still have the red wire from the BATT post connected to the large terminal as well?

[rigspelt]

If you take the ammeter out of the circuit and take the orange wire from the alternator directly to the large terminal, do you still have the red wire from the BATT post connected to the large terminal as well?

I am drafting a schematic to redesign my "new" to me old boat's wiring, most of which appears to be original (decades old). The ignition panel has an ammeter wired the classic way, with an orange alternator output wire running to the ammeter in that panel. So I am also working out the new wire runs when I remove the ammeter, replace it with a voltmeter in the cockpit, and change the alternator output from a long run to the ignition panel to a short run more directly to the battery.

I think of it this way: The starter needs power from the battery (+) post to both start the engine and maintain the engine under way. The alternator needs to get its output power to the battery (+) post to recharge the battery. Where they physically connect is a matter of convenience: in his post above, Don suggests running a short alternator output wire to the same post on the starter where the battery (+) wire connects, which puts them into continuity. (This also achieves the important secondary goal of limiting the number of wires attached to the battery posts). When the alternator output no longer flows directly to the ignition panel in the cockpit, that panel needs an alternative power supply through an appropriately sized wire.

I thknk I got that right.

[blackdove]

I'm confused!

If you take Don's suggestion and run the bigger (heavier) wire without the ammeter, can you just eliminate the two wires that were there? Makes sense to me, but these electrons could make me nuts

[High Hopes]

Dave,

I know I am in the minority, but think an ammeter is slicker than snot on a doorknob. Of course I'm an electtonics nerd, so that is expected. Here is my offering.

Steve

[sastanley]

relocating the ammeter?

Steve,
I am with you...however, I have original 30 year old wiring in my Catalina and I am going to be doing some work on the thing this winter..What about relocating the ammeter into the engine compartment somewhere, or near the batteries, so that you can keep your runs short? Then when you want to check it out (is it sending thru 4 amps or 40 amps!!!???) you can, but it eliminates that long run to the cockpit instrument panel. The voltmeter wired in the cockpit can still give you a quick glance as to voltage going into the battery.

In your diagram above, is all the green wire 8#?? (i.e. from alt to ammeter)

I realize this post is a few months old, but it relates exactly to what I am thinking, I saw no reason to start a new thread.

-Shawn
1977 Catalina 30 #511

[High Hopes]

Hi Stanley,

No, the colors are used to show what circuits are protected by the fuse. So the fuse and the wire are the same color.

I used a #8 because I have the 55 amp generator. Alternator to ammeter to battery should be #8. Most folks use #10 with the 35 amp unit. Yes, keeping the wires short is always a good idea.

I have abandonned the ammeter idea as I have simplified the wiring in the interest of time. I have an ammeter, but I would have to cut another hole for it or find a place to mount a bracket, run a few more circuits, etc. Also, I installed an Automatic Charging Relay (ACR) so even my wife, who is very knowlegable about other things, can understand how to use the battery switch which now functions basically as an on/off switch.

That being said, my ACR may not be working and I am in the midst of resurecting the entire DC system. So, I still need to do some troubleshooting; I may end up actually installing two ammeters. But for now, I hope I don't have to.

If I do, I may take one of my burnt MAXI fuses and hook the ammeter to it. That way I can replace fuses with the ammeter when I need to measure the current.

Here is the new simple-to-operate system. It's not so simple to wire. The voltmeter will be off to the right measuring the house battery at all times.

Note that this is not the normal application for a battery switch - but charging is automatic.

All the engine circuits run off the engine battery from the leads shown on the left. This includes engine meters, ingition, and the alternator current flow back to the starting battery and the ACR.

I have installed this system, but I still have to figure out how to test it. I may install an ammeter in series with the ACR. Food for thougth.
.
Steve
.

[sastanley]

Hi Steve,
Wow, now you've lost me. I'll have to re-examine your diagram when I am at work and haven't had a few beers on Friday night at home, but I am not sure if it will make more sense or not.

The current system on my Catalina 30 is pretty bastarized..It still has the original 35 amp alt. but the regulator broke long ago, so there is some weird electrical engineer stuff happening to regulate the amps into the batteries. Basically, the P.O. (my father) took a 3-way switch and added some resistors in the mix to regulate amps in the charging circuit depending on switch position.
There is also some sort of passive isolator which allows current one way, but not backwards (i.e. I think to avoid sucking down a good battery with the bad battery)


The original Catalina 30 wiring harness seems to have more cut wires in the engine bay than connected wires, which is one of the many reasons I am considering some re-wiring. But why run an #8 wire to the cockpit if I don't have to for the 30-yr old ammeter? I also understand keeping things simple for the Admiral..while she is sympathetic to an older boat (that we can afford) she doesn't like a lot of jury rigging..I am trying to simplify things for her too so that she can enjoy the boat and not be messing around with someone else's crap.


Thanks again for the detailed schematic. I am no where near that organized.
-Shawn

[rigspelt]

I updated my tentative schematic here: http://www.moyermarine.com/forums/showthread.php?t=2695. It is an example of perhaps how to wire alternative to the original panel ammeter setup. Blue Sea recommends wiring the 7610 ACR directly to the battery so it parallels the batteries for charging but not starting, leaving that task to the combiner battery switch: http://bluesea.com/productdocs/7610.

Caution: I am not an electrical engineer, just a boater.

[sastanley]

7600 or 7610?

rigspelt,
What do you think the big difference is between the 7600 and the 7610? It seems the 7610 is a better unit, and is about the same price on the internet ($70)

-shawn

[rigspelt]

rigspelt,
What do you think the big difference is between the 7600 and the 7610? It seems the 7610 is a better unit, and is about the same price on the internet ($70)-shawn

Shawn, I have not looked at the 7600, so I cannot give you a good comparison. After a really fast glance, I think the 7610 is "smarter", and maybe has higher current rating?

[sastanley]

I agree..that is why I was asking..there is some sort of isolator on my boat now, but it is not smart at all..it seems the 7610 is an economical purchase!
-Shawn

[rigspelt]

there is some sort of isolator on my boat now

Just a thought that may not apply, but if the older battery isolator technology is working well (keeping the batteries isolated but allowing them to charge fully enough for your purposes) then maybe that's good enough? ACR technology is still newish to many of us DIY small boaters, I think. I went for it because I'm doing a total wiring refit and needed something to manage charging, but I am prepared to return to a simpler and perhaps more robust(?) option for my basic two-battery boat if it causes hassles.