Getting ready to hook this gauge up. Need clarification/confidence. The directions that came show to use 14 gauge wire. One from the C+ terminal on the gauge to the Horn Relay.
Another wire from the D- terminal of gauge to the junction block behind the battery.
'67 was originally dummy lights. Reading on this site about this I have a few questions:

1) Should I use 10 gauge wire instead of 14 ga as this is what runs from the harness splice to the junction block and also to the alternator? read somewhere on here that wires need to be the same size.
2) Should I put a 50 amp maxi fuse on the wire going from my positive side of battery to the function block? What size wire for this? 14? as orig.
3) Any thing else I should know?

The alternator(external reg), voltage reg, and horn relay are all new.
Other gauges are hooked up. Gotta get that dash put back in place.
Other wiring problems ie: lights, etc have been resolved.
Gonna be driving this bad bear before long, I hope.

According to shiftworks their amp gauge is a shunt type guage, not a full current guage. That means the main wire between the junction block and horn relay still carries the current. The guage is wired as a "shunt" between these 2 points that carries minimal current, it does not replace the original wire.

Thanks, Hank.
But.....I still don't understand. I know that it reads the current between the horn relay and the junction block. More volts at the junction block shows charging and more at the relay shows discharging. or is it vice versa?
Gauge has a D- on one end and a C+ on the other. O in the middle which means everything is just right.
I have the directions that came with the gauges in front of me. That's why I asked the questions.....because of things I have read on this site on other posts such as wire size from the gauge, running a maxi fuse, etc.
Any replies to the original questions would be appreciated.
Thanks as always,

Herbie, it's not really an amp gauge. Current is not flowing through the gauge so wire size is not critical. It's actually a zero centered volt meter. There is always a voltage drop when current is flowing through a wire, it may be very small but it is there.

There are 4 variables.

1. Length of wire, which is horn relay to junction block.
2. Gauge of wire, which is 10g.
3. Voltage drop.
4. Amperage.

You know 1 & 2, if you can supply either 3 or 4 then you can use a formula to figure out the missing one. The meter supplies #3 so you can use the formula to calculate amperage. The meter is calibrated to display the voltage drop, based on the formula as amperage.

There are full flow guages but they are seldom used and not recommended. The shunt type guage is safer, since it doesn't have to carry a large amount of current. Don't change the length or guage of the junction block to horn relay wire or guage will no longer be accurate.

Thanks, Hank.
Basically, I can then run 14 ga wire from the gauge to the junction block and also another to the horn relay. Easier to do and doesn't make any difference.
The stock wire, 10 ga., is still there running from the horn relay to the junction block.
Would it be a good idea to run the 50 amp maxi fuse, fusible link, from my battery to the function block?

Thanks, Hank.
Basically, I can then run 14 ga wire from the gauge to the junction block and also another to the horn relay. Easier to do and doesn't make any difference.
The stock wire, 10 ga., is still there running from the horn relay to the junction block.
Would it be a good idea to run the 50 amp maxi fuse, fusible link, from my battery to the function block?


You don't have a fusible link between your battery and the junction block? For safety you should definately install one. Any decent auto parts should have 14g fusible links, that's size you want to protect a 10g wire.

Hey Hank, long time since you and I have both been here together!

Herbie, Hank is correct. Put a 14 ga. fusible link in between the battery and that junction block. They sell them at Advance Auto or NAPA. It's much more "spike" tolerant than a fuse. But lacking that, a 50 amp fuse can be used. One or the other, NEVER neither!!!! if you look at the factory wiring you will find 2 links at the voltage regulator. One in the wire from the alternator, and one in the wire to the horn relay. That's the same one as the one between the battery and the junction block just at the other end of the wire. Either end is fine as long you have one in there!

As for the gauge wire, I used 14ga. with a 5 amp in-line fuse in the wire to the gauge. This is just in case the wire gets pinched or shorted under the dash. It will prevent a fire and also won't take out the fusible link.

If you go to the shiftworks web site, gauge conversion page, there is a HELP link to a detailed trouble shooting process and wiring diagrams. Download, print and save those pages!!!!! Put them in your project file or notebook. You'll be glad you did. I have already refered to them a couple of times.

BTW - did you test your fuel your sending unit? I didn't and wish I had. My gauge only registers 3/4 tank when full. These gauges are meant to be used with a "90 ohm when full" sender. Some after market units are 75 ohms max. That's what I must have cuz mine only reads barely 3/4 when the tank is full. It's easy to put an ohm meter on the sending unit, lift the float and check to insure it reads 90 ohms before connecting the gauge wire to it.

Herb, how's it going? I haven't been on a lot lately but I have seen a few of your posts and some pics of your 67. You've done an awesome job, wish I had the time and talent to do that kind of work on my car. :thumbsup: I've had a lot of 'distractions' this last year, I hope to spend a little more time on the car now. Just working on the little things, you know, refinish this, replace that. Someday, hopefully, I'll get there.

Here is a Shiftworks diagram.


http://i288.photobucket.com/albums/ll182/rocks66ss/SK100-dia.gif



Rocky

FYI..Shiftworks also offers a voltmeter to replace that conversion amp gauge for a '66/67. IMO, much more useful and a lot safer.
I used their kit to replace the dummy lights on my '66 wagon's dash.

I always thought volt meters were dumb, and I used to love my ammeters, until they changed to the shunt. Since then I think they are close to being useless. I've never had one that actually moved. Well if you watch close you can see it move, a little. And then most of them have no numbers on the dial. So the information is: it's either charging or discharging, A LITTLE.
A volt meter can be installed easily with a small wire because it is a static reading. Once you get used to what it does you can have a pretty clear picture of what your system is doing.
So as of now I changed camps. I put my money on the low budget voltmeter.
I know there are a lot of die hard ammeter guys around, and that is great. Diversity is what makes everything interesting,

If anyone is on the fence here, do a search for something like "Charging Problem" or "Alternator" and I have a feeling that most of the guys trying to help will ask questions about the voltage more so than the amperage.
I have tried to help out a few times and it surprised me how many gearheads don't have a voltmeter handy.
I would recommend after the purchase of your basic wrenches, sockets, screwdrivers, channellocks, hammers, and such, the next tool should be a low cost multimeter. Hell, half of your problems can be electrical. Harbor freight sales one for about $4. Not that bad of a meter either. JMHO.
No hijack here, I will start a thread for a poll,..are you a voltmeter, ammeter, or idiot guy? I mean idiot light guy.
Squido

I appreciate it to all!!
I will put a 14 ga. fusible link between the battery and junction block. this is what the AIM shows also. The 50 amp maxi fuse goes in a holder that is on 10 ga wire.
I am glad I got two old friends back together. :-)
Herb, my gas tank was cleaned, sealed, painted and put back without the sending wire by the last shop that had it. I got a new one by UPS last night. I will drop the tank and install it. I am keeping my original sending unit. Used to work many years ago. Maybe it will read ok.
Thanks again.

I always thought volt meters were dumb, and I used to love my ammeters, until they changed to the shunt. Since then I think they are close to being useless. I've never had one that actually moved. Well if you watch close you can see it move, a little. And then most of them have no numbers on the dial. So the information is: it's either charging or discharging, A LITTLE.
A volt meter can be installed easily with a small wire because it is a static reading. Once you get used to what it does you can have a pretty clear picture of what your system is doing.
So as of now I changed camps. I put my money on the low budget voltmeter.
I know there are a lot of die hard ammeter guys around, and that is great. Diversity is what makes everything interesting,

If anyone is on the fence here, do a search for something like "Charging Problem" or "Alternator" and I have a feeling that most of the guys trying to help will ask questions about the voltage more so than the amperage.
I have tried to help out a few times and it surprised me how many gearheads don't have a voltmeter handy.
I would recommend after the purchase of your basic wrenches, sockets, screwdrivers, channellocks, hammers, and such, the next tool should be a low cost multimeter. Hell, half of your problems can be electrical. Harbor freight sales one for about $4. Not that bad of a meter either. JMHO.
No hijack here, I will start a thread for a poll,..are you a voltmeter, ammeter, or idiot guy? I mean idiot light guy.
Squido


It's quite possible you had a defective unit, or was not wired properly. I have the Shiftworks amp guage and it works and registers exactly as it's ment to, Just the process of starting the car normally the amp guage registers in the charging mode accordingly, depending on how much drain I put on battery, until the battey is back fully charged.

I assume your references are directed at the Shiftworks gauge, beings the post is aimed at Shiftworks amp meter, you don't mention any brand name, just
"I used to love my ammeters, until they changed to the shunt."

If you are indeed refering to the Shiftworks amp meter, this will be the first time I have heard of the Shiftworks gauge not operating properly.


Mine just turning the key to the on position and turning the lights on, the amp meter deflects in the - or discharge position.

Parallel wiring should not have any bearing on it functioning properly. It shows it's either charging or not.

Just for simplicity sake, if I were going to do it again, I probably would put the Shiftworks volt meter in. The face is the same and I guess only the person who put it in would know


Rocky

Well, I'm an old dog so I used the Shiftworks ammeter in the dash and and a volt meter in the cluster I hung under the dash. It's an old-school thing. We all had a 2 or 3 gauge S&W cluster hung under the dash. Put them in my new 67, in 67. Yeah, I'm that old. :yes: The factory gauges weren't much for accurate info like actual temperature, oil pressure, etc.

Herbie, my advice is to test that gas sending unit with that Shiftworks gas gauge BEFORE you install it in the tank. It's super simple to do. You just need a battery (or your trickle charger) and a couple of clip leads. Make sure the gauge reads full when the float is raised to the upper limit. 10mins. of effrot now could save hours of work later.

Volt meters and shunt type ammeters are equally safe. The reality is that a short is a short. And since there is no isolation between the source and meter, fused the same, one is no more or less hazzardous than the other.

The advice on buying an inexpensive meter is good advice IF you know how to use one and understand what it is telling you. Otherwise, just buy a decent test light and leave the electricals to a friend that does. But if you are going to buy a meter, buy a digital VOM. I've been in electronics for 40 yrs. and at home I still use a $13 Radio Shack digital meter I bought 10 yrs ago. Measures volts, ohms and continuity. That's all you need. You don't need a $300 Fluke for this hobby.

Thanks for the kind words Hank. Truth is, I don't think you are ever finished with these cars. And you are correct, it's been a long time getting to this stage! If I had it to do over again, I'd do it differently. :D

Rocky, I shouldn't have put all ammeters into one group. The ones that raise my blood pressure are the Ford trucks. I've had four of them, a 69, two 70's and a 71 all f250 and all with a non functional amp gauge. I know for a fact thatb they all came from the factory non functional. They take the wire from the alternator to the start relay and attach the ammeter wire to it about a foot apart.
Not surprising anyone for a FO*D.
I breath and bleed Chevrolet, but those old pickups are hard to pass up if you can find one for the right price. As long as you don't have to work on them. The frames are built like battleships. The one I have now is a 390, suited for towing my camping trailer.
If I could find a big block Chevy truck for cheap I would dive on it, but they are nowhere near as common.
The meter that I get at Harbor Freight is a digital VOM for about $4 and works great until on of the seven segments of the LCD readout decides to go south. I think they do ohms, AC and DC volts, DC MVolts and DC MAmps and have a socket to test transistors NPN and PNP. 9volt battery and protective case not included.
Squido

I've been in electronics for 40 yrs. and at home I still use a $13 Radio Shack digital meter I bought 10 yrs ago. Measures volts, ohms and continuity. That's all you need. You don't need a $300 Fluke for this hobby.

Thanks for the kind words Hank. Truth is, I don't think you are ever finished with these cars. And you are correct, it's been a long time getting to this stage! If I had it to do over again, I'd do it differently. :D

We're probably using the same meter, mine came from Radio Shack about that long ago. You're right about the cars never being finished but mines drivable so I only have to work on it if I want to.