The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Options for Volt meter in dash cluster

Can anyone provide me with options for an in-dash volt meter for my '66 C-10? I'm putting in an AAW Classic update kit #500560 and there is no support for the ammeter gauge. I would really like to have a working gauge in this slot. Can anyone help out with some suggestions?

1. If you tell me which one you want, an Ammeter or a Voltage Gauge, I can help you. Also provide AAW part number.
2. Advise if you already have a gauge or need to buy one.
3. Please post pic of gauge cluster.

AAW warned me against an ammeter gauge because of fire hazard. The voltage meter would be fine. I don't have a gauge, only the stock ammeter gauge that is in the cluster. AAW #500560.

Thanks Bartamos

Yes they don't support ammeters. I don't like them either.

The reason AAW is not wanting the liability is, on the Classic Update Series or any series, they don't know exactly what vehicle it will be used on or what "modern" charging output and amp draw there may be. This video explains there position. The ammeter has no fuse or fail safe device except to burn out. This will probably not cause a fire but could. If some wire burns off and is still hot, it can spark. What that spark does is the risk.

I have built a stock looking volt gauge for 53-54 Chevy car, I could do it for a 66 truck but too much work and cost you too much money.

You can wire up the ammeter or you can leave it alone and install a voltmeter in various places depending on how original you are going, and your generation and amp draw updates. Decide on what you want to do and advise.

Do you want to leave the ammeter in place (unwired) and add a voltmeter? You can add it as an under dash gauge or possibly in the large blank tach/Batt-O-Meter area in upper right cluster.

When you say "wire up the ammeter", are you saying that I could do this safely and get it to work? If so, that is what I would prefer. Otherwise, I would like to install a voltmeter in the same location that the ammeter gauge currently is.

It's probably not that big of a deal, but I would really like to have all of my gauges working, having a dead one just sitting there seems to bum me out.

The answer will depend on these answers:

1. What alternator do you have? Stock? Do you have a voltage regulator? If not stock, what amp rating?
2. What, if any, non stock electrical items and lights to you have or will have? Radio updates, amplifiers, A/C, halogen, etc.
3. What level of experience do you have with auto electrical?
4. What phase of the harness install are you at? What is done and what is not done?
5. What motor in truck?
6. Did you have all gauges working before deciding to do a new harness?

Since you don't have non stock amp draw items, the newer Alternator is OK. It will be OK, in my opinion to wire the ammeter. You are correct, you would not have a voltage reg with internally reg alt. SOoooooooooooooooooo keeping in mind AAW doesn't like ammeters and I don't either, I do understand that a stock look is best. Logic says if the ammeter was designed to read/handle loads in an original/stock truck, it will be OK. The alternator will only output what is necessary.

You WILL NOT find a way to install a volt gauge in the ammeter hole and have it look original or even good. unless you want to pay someone big bucks.

Look at pages 2 and 3 of instructions. Find the red wire from the mega fuse to the fuse panel. I believe the end at the fuse box is wired sort of permanent, so leave it terminated to fuse panel. You will cut it at the right place to do the following. Attach it to one terminal of the ammeter. Use the cut off piece for a wire from the other ammeter terminal to the Mega fuse. In other words, put the meter in series between the Mega fuse and the Fuse panel. Which terminal on the ammeter gets what wire you ask? If it's backwards, it will read backwards, then you switch wires.
It would be nice to test the gauge cluster before a tight "button up".

I actually like idiot lights for charge and oil.

Wire the other Mega Fuse wire as shown in the instructions. (starter to alt.).
Remove the alternator output wire from the mega fuse and place it on the same ammeter terminal as the wire to the fuse panel. FYI: The AAW diagram does not show that the battery positive cable is connected to the solenoid large stud.

Thanks Bartamos, that sounds pretty simple. I'll give it some more thought on whether or not I want to do this, but as said previously, I'd love for all the gauges to work.

I would really love to hear from someone who has done this and whether they found it worked for them without problems.

Thanks again. I'll post when and/if I do this.

Jeff

Would it make any sense, or make it safer if we put a shunt in relation to the ammeter?

Most, if not all, of the harness suppliers, AAW, painless, Speedway.......do not recommend an ammeter. Several do mention the ammeter and how to wire it even though they don't recommend it. It is done the way I described. However they say the ammeter rating needs to be greater than alternator output. They also say a 45 amp alternator is max. It seems they don't understand that an alternator will not produce more than the demand. Therefore a high amp alternator on a older stock vehicle with stock electrical components will do no better than the OEM alternator. Which in your case an original was 42A or 55A in 1966 or a 63A in 1974......and now unknown. Maybe you now have 100A. When I knew you had no non stock electrical, my opinion was that it's OK to use the stock ammeter. It has a shunt. I also described how to wire it. It will have a fuse. However, I do not know the rating of the Mega fuse. Seems like 175A. That will not protect the ammeter. But it never was protected. The only info I can find on their Mega fuse is 175A. That makes no sense. It's too big to protect anything. Looks like two fuses, between the battery and the alternator......and between the battery and the fuse panel.

The harness makers are trying to be clear of liability. They don't know what ammeter may be used, they don't know what components will draw how much current from an unknown alternator output rating. They know they are dealing with novices. SO they error on the safe side. I tried to analyze your specific situation and give an answer. You are on your own to decide what to do. To wait for other member's input or do nothing. I have no more info or comment on other ideas you are presenting. I give no guarantees on my suggestions.

This is why I like volt meters or idiot lights. Simple. You can now see why this always comes up during 12V conversions and harness wiring and electrical gauge questions. Ammeters cause a PITA for NO REASON. They are unsupported. They are no longer a technology worth playing with. Some old timers and purists love them for nostalgic or other unsubstantiated reasons. They don't cause a fire per se.

If you are unsure, and I don't blame you, Just get her wired and driving and worry about the charging monitoring later. Wire it per the instructions. Let the volt meter wires hang. Or install a cheap volt meter under dash. FYI: Ammeter needle is centered when off, Volt meter needle is pegged left when off.

Greetings from The Peoples Volt Meter Factory. Crick

Well spoken Bartamos. I very much appreciate your commentary and the ability to fully express your standing on the matter in such layman's terms. It has helped this novice to better understand what is going on and how to make an informed decision.
I think since the ammeter is indeed centered when it is off, that I will leave it unconnected, at least for the time being. The way I understand it even if it were activated it would only move slightly right of center, so it won't necessarily look broken. Although at this time I'm certainly not planning on adding any additional electronic, non-standard devices, you never know what might be added in the future.
I'll probably attach a voltmeter to the under dash as you suggest. Again, I thank you for your time and your sharing of knowledge.

It's amazing that we have any of the old trucks to restore, modify, and/or just tinker with. If all the purveyors of doom and gloom were even partially correct, there wouldn't be any of them left to work on- - - - -they would all have burnt to a crisp decades ago- - - - -torched by those pesky ammeters. The real reason they're not popular is the inability of the average hotrodder/restorer to understand what they're all about, and how to wire them properly to be safe and efficient. If somebody actually understood DC electrical systems and lead/acid batteries, he would insist on having not only a voltmeter, but also an ammeter, and most likely some method of monitoring the specific gravity of the battery acid. Very few professional mechanics, and virtually no average drivers have the knowledge and/or experience to properly interpret what a dash gauge is telling them, no matter if it's an ammeter or a voltmeter.

Just my opinion, supported by 60+ years of getting paid to fix cars, trucks, boats, and airplanes, and 30+ years of teaching the trade- - - - -but what do I know?
Jerry

The only thing about fire or burning up in this post is a warning from American Auto Wire and a comment from me that said: They won't start a fire. The only smoke is from a Boltergeist. But what do I know?

We have done a couple of the 65/66 Chev pickups where we put the volt meter in the circle the factory used for a tachometer. To balance the instrument cluster both a volt meter and tach are installed. Do a search for Chevy truck with factory tach to get a visual. I am a fan of idiot lights IN ADDITION to gauges since they are akin to hitting a spaced out driver between the eyes with a good sized mallet.

Evan, that idea is sort of like training a mule. Mules are very sensitive, intelligent animals, and they must be treated with kindness and care during training. The first thing to do every day when you're training a mule is to pick up a 3 foot piece of white oak 2 X 4 and smack the critter HARD between the eyes. This gets its attention, so the kindness and care part of the training session can begin. Ditto for idiot lights- - - -the name says it all! The idiot lights on my Ram 1500 truck also sound a loud chime tone when they illuminate- - - -which is definitely a good thing!
Jerry

I have a digital voltmeter that plugs into the cigar lighter outlet. It also tells me the inside cab temperature and it has a USB port. Cheap on Amazon.

If you don't like looking at it, just throw it in the glove box.

Late to the party here but this is a concern. If wired as described the ammeter will NOT work properly. The ammeter should be installed in series between the mega fuse and the starter. Not in series between the mega fuse and the fuse panel. If installed between the mega fuse and the fuse panel the ammeter will only indicate amps going into the fuse panel, not the rate of charge/discharge. Installation of an ammeter in this autowire kit will be cumbersome to say the least. There are better ways.

Mark

"Late to the party here but this is a concern. If wired as described the ammeter will NOT work properly. The ammeter should be installed in series between the mega fuse and the starter. Not in series between the mega fuse and the fuse panel. If installed between the mega fuse and the fuse panel the ammeter will only indicate amps going into the fuse panel, not the rate of charge/discharge. Installation of an ammeter in this autowire kit will be cumbersome to say the least. There are better ways.

Mark"

Mark, my thought was that if you see the mega fuse as a terminal block with wire across instead of fuses, then it would read all draw from the terminal block. When it was split into two fuses, its still the same as one hot terminal block. So therefore ammeter reads it all. Also other instructions for wiring harnesses that support ammeters say put it between the fuse panel and the battery source. It seems like wiring the way I said, does that. I do see what you said makes more sense. I do see the whole exercise of keeping an ammeter while installing a modern update harness as "cumbersome", that is my main point. But if a person wants an ammeter, then you should post "Your better way", using the AAW harness he has.

Otherwise I would agree with Mark's advice to put the ammeter between the mega fuse and the starter and let it remain un fused. My purpose is to try and install an ammeter with a harness that does not support it. I take no responsibility for any trouble that may result.

Good point about the need to provide fused protection for the ammeter. After more thought here is what I would do if this were my truck and I was committed to the AAW harness. I would modify the wiring diagram and connect as shown in either one of the photos attached. You are correct, the 175 amp fuse does not provide good protection and I would drop down to maybe 50 or 60 amps fuses. Also be sure to keep the fuses independent and do not use the jumper shown in the original AAW diagram. Mega fuses should be mounted under the hood, not under the dash. If I have a good solid post on the ammeter I would connect the fuse panel directly to the ammeter, same terminal as the alternator feed wire. Otherwise run the 10 gage fuse panel wire to the mega fuse terminal. Use 8 or 10 gage wires for the added ammeter connections. This modified diagram provides fused protection for fuse panel and ammeter.

In my opinion one 'better way' is to start with a fuse panel that includes both a alternator feed and a battery feed. Simply wire the ammeter in series between the fusible link at the starter solenoid and the battery feed terminal on the fuse panel. Painless has such a fuse panel and that is what is used on my truck, including full function ammeter. No problems in many years and thousands of miles.

Mark

Why not use a fusible link like all the automotive manufacturers do? I think Forrest Gump's Mama had a saying about some people that applies here!
Jerry

So to charge the battery, the alternator goes thru a mega fuse, then thru ammeter, then thru another mega fuse?

If the mega fuse is a fuse holder, Mark would replace with smaller fuses, I believe is what he is saying. In the interest of using kit parts. Replacing with fusible links is an option also. All ideas are worth something in this village. Pompous is as pompous does.

Agreed. As noted, I use a fusible link. The challenge was to install the ammeter with the AAW harness.

I have modified the last sentence of my original suggestion. I have written ammeter wiring on several posts and don't know why I missed this last sentence. You will notice in my modified portion in red, I used the mega fuse for one circuit and a fusible link in another. Mark has two good diagrams for wiring. However, he shows the mega fuse split into two mega fuses. I do not know if that is possible or if it is built with the hot sides permanently connected. The AAW diagram shows they may be. So I mention one wire can use a fusible link just in case. As has been stated, both can use a fusible link and abandon the mega fuse. To reiterate, the battery hot goes to one ammeter terminal and all other wires, I.E. alternator output, fuse panel feed, goes to the other.

Fusible links are sized 4 gauges smaller than the gauge of the wire. Example: 12 ga wire gets a 16 ga Fusible link. They are just a piece of wire with extra burn protection insulation. The wire, or a coupling, burns in half before damage is done to a component.
Click

Mark, What is confusing is that you say my statement was in error (actually it was only my last sentence) and issued a new statement, yet your diagrams are not per your statement.

The ammeter should be installed in series between the mega fuse and the starter. This is not what you show.

Not in series between the mega fuse and the fuse panel. This is what you do show.

Both your diagrams are correct. I know what you meant, I know that you know what you are doing. We both got mixed up trying to use a double mega fuse which has one end as battery hot. We both know that all draws are on one side of ammeter.

I felt it necessary to explain the situation in my last two posts for the archives. I hope I have not made it worse. Other wiring harnesses from other companies will have a different explanation as you have eluded to with painless. Some harnesses do not support ammeters, some mention it and try to explain and some do not mention it at all. I have instructions for Speedway Auto PN 910-64017 dated 2009 which mentions how to wire in an ammeter. The 2019 instructions for 910-64017 now have no mention of an ammeter. So just a few of us left to help folks keep their ammeter (against my advise).

This post is a factory 12V case. Hot Rod Jerry has at least one post telling how to make a shunt for an ammeter using a piece of hose clamp. That case was a 12V conversion/rewire and how to keep the "so called" 6V ammeter. Click