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Ammeter Wiring

S

Steve Kirk

Does anyone have a diagram of how to wire the ammeter in a series 5?

Thanks
Steve
 

Jeff Scoville

Donation Time
There should be a large (10ga or so) Brown wire going from the starter solenoid switch (which also connects directly to the battery +) to the "A" terminal of the control box.
You can cut this wire and install the gauge in line.
The gauge will have markings for polarity, (being this is a Series V, you should have a neg. ground vehicle) connect the - to the end going to the control box, and the + to the wire going to the solenoid/battery.
 

Nickodell

Donation Time
Jeff, I'm not sure what you mean by "control box." On my SV the brown wire goes directly to the fuse block, and the various circuits lead off from there.
 

Tom H

Platinum Level Sponsor
Opps , Sorry . After posting I realized that this diagram does not include the Ammeter. But maybe it will help you understand the other posts. And do note that the item called "voltage regulator" on ths diagram is the small instrument voiltage regulator mounted behind the dash and the item called "Control box" is the main regulator - the thing most of us call the "violtage regulator' on our regular cars.

Tom H
 

64beam

Donation Time
Hi Steve,

As Nick described, follow his directions for the wiring of the ammeter. As all of the electrical load of the car will now run through the ammeter, be sure that the wiring is large enough. Even allow a bit up your sleeve. You may also have to re-route some wiring. If you have WSM 145, there are some other models that show an ammeter in the wiring which is very similar to the Alpine wiring.

Regards, Robin.
 

Tom H

Platinum Level Sponsor
Steve,

I'm afraid we have not been much help. The diagram I linked does not show an ammeter. Robin's message says follow Nick's advice, but Nick had no advice. And Jeff's advice, which I said to follow, is wrong. Jeff refers to a brown wire going from the starter solenoid to the "A" terminal of the control box, but there is no "A" termnal on the Control Box, just +, - and F and furthermore, as you can see from the diagram, there is no brown wire going from the Solenoid to the Control Box at all.

Let me try again:

See the color diagram. You see three brown wires and the large cable from the battery connected to one post on the solenoid. With an ammeter, according to the WSM, and as installed at the factory, all three brown wires would instead be connnected to the A terminal of the ammeter and one new brown wire would go from the solenoid to the B terminal of the Ammeter. Thus all current for the car: charging current, ignition current, lights, etc, all go through the ammeter. Only the starter current does not. This would be the correct way to wire it. But it may be difficult to move all three wires from one side of the firewall to the other and still tougher to make three heavy connections at the ammeter.

An alternative, which I did, would be to remove all three brown wires from the solenoid, add a new brown wire - of similar heavy guage (#10?) - connected to that solenoid post and run it to the ammeter. Keep it short. Then run another similar length of the same heavy brown wire from the other terminal of the ammeter back to the area near the solenoid and make a connection to the three brown wires you disconnected from the solenoid. How neatly you make this 4-way connection is up to you, but I'd suggest you use some sort of terminal block and / or tape it up very carefully! If this connection makes contact with the body of the vehicle, sparks will fly. Or worse, if it happens when no one is looking, a fire may result! This terminal is live connected to the battey with no fuse - unless the ammeter may act as a fuse!

Regards,

Tom H
 

64beam

Donation Time
Hi Steve,

Tom is definately correct, we have swayed off course :eek: and Nick was trying to explain the procedure. If you have a look at the WSM 124 (late series IV) as a reference, it shows the ammeter in the circuit which can be used in conjunction with the series V diagram (very similar other than the alternator & positive earth). If you are finding the procedure difficult, seek an auto electrician.

Regards, Robin.
 

Tom H

Platinum Level Sponsor
Paul,

The problem is you are refering to a SII diagram, which has positive earth, a Generator, and a different control box, one that has a "terminal A". Steve has a SV, so it is hard to make the transfer of understanding. In the SV we have neg earth which means the ammeter get wired opposite direction, there are THREE brown wires connected to the solenoid, not two, and none of the brown wires goes to a "terminal A of the control box" . Furthermore there is no single wire in a SV that is equivalent to the SII wire from Terminal A of the Control box to the solenoid. So there is no way to interrupt a single wire on a SV and install an ammeter. That's why you need to do it the way I described. Unless somebody else has a better way.

Tom H
 

v13311

Silver Level Sponsor
Some of us have replaced the Lucas with the later Hitachi (Datsun) alternator and bypassed the 4TR Control box. My alternator (Hitachi) charges fine and the ignition warning light works correctly. However my ammeter only shows a charge-Never a discharge. In fact, the more accessories I turn on the greater the charge is indicated on the guage. With the ignition off and I flip on the lights, no charge or discharge is shown on the guage. Anyone have this figured out?

Help appreciated.

Ed
 

Nickodell

Donation Time
Ed, it appears that you have the ammeter wired into the alternator output circuit, so it only shows the output from the alt, and does not indicate drain, so the more accessories you turn on, naturally the more the alternator puts out and the higher your ammeter shows.

Interestingly, in most light aircraft the ammeter is wired exactly this way, for a reason I've yet to discover. Maybe Rick can explain the logic.
 

64beam

Donation Time
Ed, it appears that you have the ammeter wired into the alternator output circuit, so it only shows the output from the alt, and does not indicate drain, so the more accessories you turn on, naturally the more the alternator puts out and the higher your ammeter shows.

Interestingly, in most light aircraft the ammeter is wired exactly this way, for a reason I've yet to discover. Maybe Rick can explain the logic.

Hi Nick,

This is how my Alpine is wired as well. I am actually running an alternator with a built in regulator so does not need the control box (voltage regulator) as needed with the Lucas alternator. My ammeter wiring run from the solenoid through the ammeter then to the fuse block and then basically stock Alpine after that. The ammeter shows the load being used.

Regards, Robin.
 

Tom H

Platinum Level Sponsor
Ed,

It doesn't matter if you have a newer alternator with built in reg. If you wire it as I described it will work correctly. Remove all wires from the terminal on the solenoid where the battery is connected, except leave the battery cable connected. Then run a heavy wire from that terminal on the solenoid to the ammeter. Then run another heavy wire from the other terminal of the ammeter back to near the solenoid and connect it to the wires that used to be connected there. Thus all current to and from the battery go through the ammeter, which is the normal intent.Note that my description appies to changing from original. I do not know exactly how yours is wired now.

Robin, I don't think yours is wired the same as Nick's. Nick says his shows the output from the ALT. Some of that current may go into the battery and some may go into the lights etc. You can't tell which. It's not the worst way to wire it, but not quite as informative. From your description yours seems wired to show what current goes into the lights etc. Some may come from the Alt and some may come from the battery, but as your ammeter is wired you cannot tell. If the alternator quit, you would still show the current going to the load, but you would not know that it was coming from the battery (until it dies!!), and not from the alternator. That's why it is wired wrong.

regards,


Tom H
 
S

Steve Kirk

Tom and everyone,
Thanks for the help I now understand exactly what I need to do. I will install new wires as I do not like joining wires. The previous owner of this car did just that with some crude tape joints and I was unsure of the way it was wired. I will hopefully do this on saturday.

Steve
 

64beam

Donation Time
Ed,

Robin, I don't think yours is wired the same as Nick's. Nick says his shows the output from the ALT. Some of that current may go into the battery and some may go into the lights etc. You can't tell which. It's not the worst way to wire it, but not quite as informative. From your description yours seems wired to show what current goes into the lights etc. Some may come from the Alt and some may come from the battery, but as your ammeter is wired you cannot tell. If the alternator quit, you would still show the current going to the load, but you would not know that it was coming from the battery (until it dies!!), and not from the alternator. That's why it is wired wrong.

regards,


Tom H

Hi Tom,

I misread the post from Nick. You are correct, I have it wired similar to ED's which shows the current being used by the vehicle not through the alternator. If the alternator fails, the indicator light should come on and I also have a voltmeter installed which shows the alternator is working by the 14volt reading when running. Also the way I read any of the wiring diagrams that show an ammeter, they are wired similar to the way I have wired it. Solenoid to ammeter, ammeter to control box/alternator relay (in my case fuse box) and then to the fuse unit. If every diagram I look at is the same, obviously Rootes stuffed up too :confused: .

Regards, Robin.
 

Nickodell

Donation Time
Nick says his shows the output from the ALT. Some of that current may go into the battery and some may go into the lights etc. You can't tell which. It's not the worst way to wire it, but not quite as informative. Tom H

No I didn't:mad:

I opined that Ed might have his wired that way. Mine is wired to show both output from alt and load from accessories, in this way indicating everything you need to know.
 

Tom H

Platinum Level Sponsor
Robin,

As long as the wire goes from solenoid to the ammeter and then from the ammeter to the "other stuff", with no other connections at that same solenoid terminal (except maybe an incidental small circuit like a courtesy lamp), it is OK. The problem is with the SV, which unlike previous models, uses the solenoid connection to the battery as the main junction point of three main circuits - the big cable from the battery, the charging current from the alternator circuit , and the feed to the power-using circuts of the car. In older Alpines the second two circuits are connected somewhere after the solenoid,so it is fairly easy to put the ammeter in that circuit. where it can monitor current coming and going to and from the battery. In the SV, it is easy to put the ammeter in one or the other circuits, so you can monitor the current going to the car or coming from the Alt, but not both. That's why I suggested Steve put the ammeter between the solenoid AND the junction of the other two circuits, which means locating that junction somewhere other than on the solenoid.

You, of course, are in good shape with the indicator light and the voltmeter to let you know how your charging circuit is doing. But this ammeter location issue has messed up many SV users who end up with only an ammeter telling them either how much current the car is using (not very useful) or how much current the ALT is putting out (more useful), but not how well their whole charging system is working (most useful).

Properly installed an ammeter will show. A)With car not running, the ammeter will show NEG amps of how much current the lights etc are taking from the battery. B) After starting, the ammeter should show POS amps indicating that the ALT is putting current into the battery, replacing the energy that was taken from the battery during the cranking of the starter, while also supplying the operating current to the car. It should be a lot POS for a minute or so and then back off as the battery gets refilled. C) Even at idle a good Alt will be still putting the ammeter POS after starting. D) at idle, if all the lights, blower etc are on, you may expect the ammeter to go slightly NEG since the power used may exceed what the Alt puts out, so the battery supplies the rest. But increasing engine revs a bit should put it back to POS or at least mid scale. E) At road speed the ammeter should still be slightly POS for many minutes after starting. F) After many minutes at road speed the Alt should have fully recharged the battery - while also supplying the car circuits needs. The ammeter should be at 0 or mid scale, indicating that the battery is charged so no more current is going to the battery and the Alt is fully supplying all the current the car needs. G) If the ammeter goes NEG while the motor is running at some reasonable revs (2000 or so?) then the Alt (or associated circuits) are not working right and instead the battery is supplying the electric power to the car. That is what an ammeter is supposed to tell you.

I hope this is helpful to any who do not understand ammeters in cars.

Tom H
 

64beam

Donation Time
Hi Forum,

What a great topic ;) . To help understand a bit better I found another helpful drawing that only looks at the charging circuit. Have a look at the attachment.
 
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