Frist picture( was on my phone)
The plastic insulators will cost you points.
Ok had something odd the other day after I ran the car for ten minutes I noted that on my new VOLT meter after turning off the switch it showed voltage. The problem is I knew I had it wired in wrong and was to work on that but the way I had it wired in it was not showing an voltage. After I turned off the switch it showed 6.4 all the time. I knew this would drain the battery if left as is. Sunday I took it out and then with a test light found batter on all the time, even voltage going to the cutout, so I removed the screw on the far right.
My plan was to wire the volt meter in with my dash light so that I could check the voltage when the light was on. For now the switch has an extra lug that is mark ground and is where the black wire from the meter goes an will be changed.
Do I did I have my yellow wires on backwards?
You have an extra wire there.I would forget the ground connection on switch and wire the amp gauge up per the wiring drawing.Did you get pictures I sent you?
I think he said it's a VOLT METER.
The volt meter will "run" all the time unless you install a separate switch to interrupt the ground wire for it. But, the volt meter doesn't draw enough current to discharge the battery. If in storage, you should disconnect the battery and put a maintainer on it anyway.
Here is the wiring diagram I used. Wiring in a volt meter is a little different, for now disreguard the volt merger and think why my lead to the cutout is hot all the time.
Looking at this dia. I have the correct yellow w blk teacer wired correct, Is it normal for battery voltage to be present all the time going to the cutout?
Jerome, yes, voltage is always at the cutout. That is why you have one. Unless you are running a distributor and have modified the wiring to be live only with the key to battery, there will always be voltage at the cutout with the key off. Take a look at Ron Patterson's schematic. I hope I'm using the latest version.
Ok I'll not worry about the voltage at the cutout. I guess I did/do have it wired up right. Odd that after it ran for a wile I found a good ground and then my volt meter started working. I finish up the install of the meter being switched tomorrow and put it all back together.
Yes, the cutout sees voltage all the time. (But the generator post doesn't.)
The two loose-end yellow/black wires should be connected to the BAT terminal of the switch. That stays the same for an ammeter or volt meter. You have the yellow (battery feed) and the yellow/black jumper tied at meter correctly. The negative side of the meter needs to go ground or a switched ground.
If you want the volt meter to register only when the engine is running, you need a separate wire from the generator post to the + side of the gauge then ground the - side. If you do this, the yellow/black jumper is eliminated and the yellow battery feed would be connected to the BAT terminal on the switch along with the yellow/black wire from terminal 1.
I think this is the most recent version of Ron's diagram. I've removed the paper background.
Actually, that's my modified version of Ron's version. I replace the script with block letters.
That doesn't work with a VOLT METER.
The diagram below shows the "Alternate Method" of connecting a volt meter if you want it to register voltage only when the engine is running. It will indicate voltage generated buffered by the battery.
The advantages of this method are two fold; The volt meter is off when the engine is off and it can alert you to a stuck cutout that will drain the battery.
The disadvantages are that you must add a protected wire from the generator post to the gauge. And, this does not protect the volt meter should you loose the battery feed circuit and the generator goes into nuke mode.
Forgot to mention:
If you are using a Voltage Regulator instead of a Cutout, the volt meter should be "saved" by the VR when it shunts the generator to ground on loss of the battery circuit. If the engine is running and this condition occurs, the volt meter will drop to zero and indicate a problem. Such as a blown fuse in the battery feed circuit, if you added one.
Rewired everything today but the voltmeter, I spent an hour and a half looking for my cloth covered wire that I had special ordered just for this with no luck so I gave up then tonight when I returned to the house I spent an hour looking through everything again and I found something I hadn't looked in before and in there was my wiring, I like the idea of a fuse in line, thinking a 2 amp should be ok. I plan on coming off the battery post on the terminal block right where the horn is powered as I don't like the idea of running a wire all the way to the generator. I'll do that on my truck an speedster.
I will post more tomorrow as I have a question on wiring g up the dash light.
Here is what I did. Some may not think it was worth the effort. I really hated the idea of mounting a switch or running a wide down to the generator.
It has a 3a fuse run from the tail light lug on the back side of the switch and because it has a ground lug the circuit is then self contained to the switch panel.
Why did you mount a fuse there? A 3A fuse won't save the volt meter if the generator goes nuke. The voltage can be over 15+. It will go just like a light bulb--Ffffit, then the good smoke comes out. The meter will still only draw a few milliamps.
Ok so 3a is too much? Find a .5a fuse or do I need to place a limitor of some type to keep voltage under 8 volts. One thing I forgot to put in my post is that the headlight switch is my bolt meter switch. All I have to do to check the voltage is flip the headlights on.
A fuse protects against over-current not over voltage. The meter will never blow the fuse unless there's a short in the meter itself or the meter + post. You might check with Fun Projects (John) and see if the meter has some internal protection against over voltage.
I'm not an electronics guru but there may be a voltage limiter (regulator) available but I'm sure it will induce losses. Best to check with John.
I was just looking at a simple Zener diode circuit. They're available in 8.2 volts. Perhaps it's already incorporated in the meter. Dunknow.
I believe you want a fuse between the starter switch and the terminal block. Yellow wire. That is what John recommends.
Also if you have a fuse behind the switch, how will you know if it blows and how are you going to get back there to replace it?
Good to hear you have it running. When is Julie going to learn to drive it?
Modern vehicles have used a volt meter on the dash for about 30 years or more.
The main reason for the change is that the voltage is more significant than the current.
Then too, my newer vehicle has a generator capable of a 100 amps output and a trickle charge would not show on an ammeter.
The volt meter has little or no use for a Model T generator with a 10 amp output or am I missing something here?
A voltmeter with expanded scale gives you a close look at a narrow range of voltage that is only really useful to monitor the battery. If you connect your Fun Projects voltmeter directly to the generator you will very likely destroy it when the connection to the battery is not there and it will not provide you any real useful information about the generator in the short life that it will likely have because you connected it to a source of potentionally 3 or 4 times the normal max voltage of the battery that the meter is designed to be connected to. You also have it connected ahead of the cutout which if a diode type will make the meter read higher than the battery voltage and if the cutout it mechanical then the voltmeter will get a huge inductive "spike" every time the cutout opens and closes. No warranty on that - sorry. The meter typically draws less than 3 mA so you can leave it connected to the battery if you drive the car at least once in 90 days or so. Modern cars have parasitic drains from memory devices in your car that when added together can typically reach about 50 mA of constant drain by comparison. Since antique cars can sit longer than 90 days without being driven it is prudent to put a small switch in either leg of the voltmeter connection so you can flip it off when the car is going to be stored. A fuse in series with the voltmeter does nothing to protect anything and over voltage at the battery sufficient to hurt the meter itself is not likely to happen before the battery explodes assuming it to be a normal size automotive battery. If you prefer the voltmeter to an ammeter or have an alternator in the car which can easily damage an ammeter then just tie the 2 ammeter wires together and place them on the positive (+) terminal of the voltmeter to thus join them and to provide the positive connection to your voltmeter. Then run any size wire from the negative voltmeter lead to a metal actual ground connection on the car (not to a free floating "ground" terminal on the ignition switch which is not connected to a real ground). If you want to place a small hidden switch in that meter ground wire to disconnect the meter you can put it there. Put a single fuse in the battery path by mounting it at the starter foot switch location. That fuse does nothing to protect the voltmeter but it will protect your car wiring better than any other device. Multiple fuses everywhere really cause more loose connections and trouble and do not aid in service diagnosis or add any additional safety over the single simple fuse IMHO. Don't overthink the issue since you will install more problems while solving none.
Another thing that is often overlooked is there are two different looms used under the dash. One is for tourings and roadsters, and the other is for closed cars, which is about 12" longer. The repros are the longer variety, which is not correct for open cars.
Larry you got that right this one is to long. Tomorrow I'll move the fuse to the starter switch. I will also post a pic of the panel after I make my change.
John - How often does a cutout open and close?
Doesn't it close on engine start up and open on shut down? There shouldn't be a spike as the energizing coil is always connected, even as the gen spins down. That's one of the drawbacks of using a cutout--It's always charging the battery while the engine is running.
Also, voltage at the gen post and cutout will ALWAYS be higher than the battery voltage when the engine is running.
If you are using a cutout (not a VR), I would advise you NOT put a fuse in the battery feed circuit. If there's a short in any circuit causing the fuse to blow, your generator could be destroyed before you could pull to the side of the road. The only way you might know that it happened is if smoke is coming from your wiring or you're driving at night and your lights flash and burn out.
Depends on the speed of the engine at idle and the setting of the third brush as well as the "operate" voltage threshold of the cutout. The idea that the generator is always charging regardless of engine speed is not guaranteed.
I respectfully disagree with an attempt to save the generator by NOT putting a CORRECT sized fuse in the main battery feed point at the starting foot switch. Since the correct fuse for that point is a 25 amp fuse and could not be blown by the generator in any normal 3rd brush setting - how on earth could somebody possibly be better off with no fuse at all to blow when there is current in that main feed line that exceeds 25 amps!!! With that much current there is a direct short in the wiring somewhere! With more than 25 amps in that main feed line you wiring is about to burn up completely so who cares about the generator at that point - your entire car is in danger and the generator can be repaired. Main fuse that I advocate for is for catastrophe prevention and is a 25 amp fast blow fuse. I understand your concern for the generator but wouldn't the whole car be more of a concern.
Most folks don't start their car and let it idle all day. They get in it and drive. It only takes 400rpm or less to exceed battery voltage. And if there's a short in a headlight wire, it will blow that 25A fuse and burn up a $400 generator. It doesn't have to be a "dead short". A chaffed wire that intermittently shorts can blow that fuse and your out another $400. Fine and dandy if you sell generators.
It's not enough to just fuse that battery circuit.
If I could predict the exact failures of the wiring then all sorts of conclusions can be drawn as to what would be best but problems in wiring are not concrete and are not predictable. If a problem is totally predictable then it can then easily be prevented and is not part of the reason one puts in a fuse. I believe it is prudent to have a main fuse that can and will blow when the wiring is overloaded - I repeat you cannot possibly be better off not having that fuse at all because of damage to some one item but I also would point out that a short in the wiring that would blow that fuse would also be a short on the generator and thus the generator would not likely be harmed in the scenario that blows the main fuse.
I also would point out that a short in the wiring that would blow that fuse would also be a short on the generator and thus the generator would not likely be harmed in the scenario that blows the main fuse.
No sales pitch because I don't do generators any longer but all generators I've done since about 2004 are automatically protected against a loss of the battery circuit.
And I'm a proponent of fusing the lessor circuits with lower amp fuses. Keep the high amp battery circuit fuse as a last resort. That's how modern cars work.
It's easy to hide the fuse block under the dash and behind the terminal strip. The necessary jumpers can be made from the harness that passes through the firewall. From the outside (engine compartment), no visible changes will be detected. This can also protect your switch from being cooked.
Got it all done but for moving the fuse to the starter switch. Need to pick up 25Amp fuses. The light works, the spring loaded pins when the switch rotates pop off the bottom of the bulb. This is not a problem because I can then rotate it back and the contacts hit the bulbs tips on there sides and the bulb lights up fine. Because I won't be keeping it lit for very long this works for me. The volt meter is for right now on all the time. Later I'll put a switch in the ground wire. I moved the two large wires from the batt on the switch to the meter, then used the amp wire from batt to the + side of the meter. Grounded both the light and meter to a grn on the dash. Now the meter reads higher than before, my guess is having a much better grn is the big factor there.
Here is the finished install. Everything is working and the pic with the lights out taken with my phone you only see a glow. I will later wire in a switch for the volt meter when I no longer drive it often enough.
(Message edited by jh1427 on November 14, 2015)