Ampmeter connection

[Raider L]

@DoubleDingo,

Yeah, that's what I thought to. Oh yeah, it'll be a 3/8" ring to fit on that bolt And I'll put it under one of those star washers on there I was telling @Ellie Niner about to look at. That block with all the power wires on it. Someone mentioned some time ago that I probably should try to cover that block since all the dang power in the truck is right there!! If a wrench hit that by accident and I didn't have the battery cable disconnected, boy wouldn't that be a big a** spark and smoke and god know how bad it would be. Plus I'd probably be laying out in the yard somewhere!

That #8 ring connector will need to have a little bitty ring diameter on it since the posts on the gauge are the same size as a regular gauge. They aren't large for the current it'll be carrying. I suppose it's what happens inside that's important though.

 

[Ellie Niner]

@Ellie Niner,

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Boy this is about as close to "real time" as I can do. Here is where I want to connect the amp. gauge up to instead of going all the way down to the starter. What do you think?

The large red cables are:
1) Starting with the big bolt in the middle, excluding the #12 red wire to the left of the big bolt, the big red cable IS the battery cable. That big bolt is a bronze bolt and nut.
2) The next large red cable to the right IS the power cable going to the starter.
3) On that same big bolt, the wire that is up at an angle is 12 volts going into the electrics in the cab through the fuse block. That's the one that curls back up to the fusible link on the firewall I was going to use.
4) To the right of the big bolt is a sticker marked "S" is the purple wire going to the starter.
5) Next to it with a sticker marked "R" is one of the starter wires I think that is part of the fusible link down there. I was told by Autometer to put a shunt on this wire so as to stop any back flow of electricity while the starter is stopping, to protect the system. I haven't had any problems from it so far and it's been 25 years so I guess they knew what they were talking about.
All those wires on those posts, "S", "R" go inside the cab to the starting wiring.

Okay, yeah. That'll work just fine... I had a braindead moment when you mentioned junction block- d'oh! Now, I see three larger gauge red wires (one is kind of hiding behind another). Isn't one of those coming from your alternator? The wire coming from the alternator is the one you need to pull off of the terminal block and extend through the cab to the "A" terminal on your ammeter. Then you run a wire back out to your pictured junction block from the "B" terminal on the ammeter. I prefer ring terminals to the "U" shaped ones, as they aren't always slipping out while you're trying to tighten the nut, and they do have a bit more surface area.

Can't tell from photos, but most wire does have markings denoting gauge size on the jacket, though OEM and really cheap stuff sometimes doesn't.

You've got most of your stuff organized a bit better than I do... most of my commonly used bulbs and fuses are in a cabinet with 39 bins (just counted), but others have spilled out into cups, boxes, and Ziploc bags. I have a tendency to just pick up those small bits on wrecking yard trips, but I might go a little overboard... Relays, flashers, timers, chimes, buzzers, sealed beam headlights in all sizes, and the list goes on. My quarters are pretty tight right now, so hard to get any good pictures.

 

[Raider L]

@Ellie Niner,

Yeah, you'd be shocked to see actually how small my "shop" is where I took those pics and do all my work. It literally measures 6 X 10!! The shop I had at the house we built out in the country

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and lived for many years had two ten by twenty buildings tied together. It was great. But then we moved into the city and I built this building mostly for storage and what was left over was for my new "shop". It's ridiculous. But I have built some big stuff out of this matchbox. I just extend it out the door outside!

One of those red wires may be the wire coming from the alt. I'll check it tomorrow. And as far as the terminal "A" wire coming from the amp gauge, what do I attach it to on my block, that big bolt in the pic?

Here's the pic I took of the whole wiring at the block I put in. You can see where that wire is on the battery side of the fusible link. I was going to hook the "B" wire there and I guess the "A" wire at the big bolt. But of course I'll do it like you advise. That big red wire is the one that is angled up to the right from the big bolt. That's the same wire at the link. Strangely enough the wire on the other side of the link is the blower fan power wire. It's the only one on that side. Weird.

So If I hook the alt. wire to "A" then where does the alt. get it's power, through the amp. gauge?? Man!!

 

[Ellie Niner]

The feed from the alternator is the one you remove from the junction block (I'm presuming it's one of the three there) and extend it into the cab to ammeter terminal "A", then run a new wire from ammeter terminal "B" back out to the big lug on your junction block. I'm also assuming that every circuit in the truck gets its power from there, as it goes from there to the battery terminal on the starter solenoid.

And yep. The ammeter itself is basically a straight-thru from one wire to the other; it just measures the current flowing through its windings and magnetically deflects the needle one way or the other. If you hooked it up backwards, it would just read backwards: Charge when it's discharging and Discharge when it's charging.

 

[Raider L]

@Ellie Niner,

Okay, I looked a minute ago at the alt. power wire coming from the alt. up to where it goes up there on the firewall. Go to the last pic where you can see all those wire and specifically at the fusible link connections. You'll notice there are what appears four wires at the link, a large red wire, a smaller red wire along side of it, and another wire that looks like a light blue wire, and a black wire. I have no idea what that light blue wire is because when I looked at it just now it goes nowhere from the connection there with the two other red wires.
The smaller red wire that's under the tape with the large red wire, at the link, IS the alternator wire.
So based on what you are saying, the alt. will charge the battery from the amp. gauge connection inside? I'll take that tape off those wires at the link and look at what the heck is going on in there because I didn't make that up. That's factory. The only new connections I made were the starter wiring at that block I put there on the firewall so they would all be together. One of the reasons I did it that way was to make it easier to hook my remote starter switch to some starter wires so I could jump the engine over to reset valves and whatnot.

That black wire that is with the others that go to the link, is actually the old factory amp gauge wire and that tapered thing with the zip tie on it the black wire comes out of is one of the two fuse holders. I'll cut that wire out because it's not of any use in the system now.
So could I solder my "A" wire coming from the gauge to that alternator wire right there? And then run the "B" wire coming from the gauge to the big bolt? Now all I have to is get more #10 wire. I have that small amount of #10 that's black and you can see in the pics above that I'm holding, that I think will make it to the link connection, just in reference to the distance from the gauge in the instrument panel to the link.

 

[Raider L]

#Ellie Niner,

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Double--disregard

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Isn't this amazing!! This is what was under the tape. I had a hard time removing the tape. I had to use a #2 X-acto knife to cut, scrape, and pull bits and pieces of the old tape off until this is what was revealed! I can't tell if it's soldered or what. I don't see any solder. It looks like it's just twisted together but it won't unwrap. I'll guarantee you I didn't do that, it's factory. I redid what needed to be redone, and left what I didn't need to redo. So this is what that light blue wire was connected to, the alternator wire. You can see the fuse holder there. It's the old factory amp gauge wire, black with a white stripe, that is going to the link post where the big red wire is connected.

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And I'll put a terminal end on the "B" wire and connect it here. The light blue wire will be gone and the only wire left will be the big red wire that goes to the battery cable on the block below.

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Then I'll connect the "A" wire to the alternator wire here.

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Double- disregard.

 

[Raider L]

A couple more pics. Just the old amp gauge wire and fuse holders. If anyone needs these amp gauge wire and fuse holders let me know and I'll send them to you. Don't worry about S&H I'll take care of it. I remember someone needed these things in a post not to long ago and couldn't find them. I'll take the whole wire out from end to end if I can get it past the fuse block at the firewall. Otherwise I just cut it and solder it back together.

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This is the end down near the fuse block, the second fuse. There are two 10 amp fuses in these holders. I'll leave them in for 'ya.

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Somebodies mess. It ain't mine! I would never do anything so unprofessional!

 

[Ellie Niner]

@Raider L I'm pretty sure I'm following you, and it sounds like you've got it right! I remember those two fuseholders on my 1975... I recall there being 3amp fuses in there on mine. I had a rough time getting the factory shunted ammeter to read correctly... it tended to only twitch the needle either direction a tiny bit, no matter what the load or rate of charge was.

 

[Raider L]

@Ellie Niner,

Thanks for your help on this, and @DoubleDingo to.
What do you think of what I found where the Alt. wire was connected to that short piece of light blue wire that goes to the fusible link there? Isn't that the craziest thing you've ever seen. I'll guarantee you that is factory. It's been taped there ever since I've had the truck. And when I was rebuilding the truck and the electrics, it looked okay and I just left it alone. And I've owned this truck since 1981!

So by the diagrams I've looked at since your earlier comments, running the "A" wire to the battery side of the fusible link and like you said the "B" wire to the Alt. wire is the way to go. I went to O'Reilly's today and they had all kinds of #10 wire. It's what the Autometer directions say to use so I'm going with it.

I must not forget to just, "turn the key on then turn on the lights", like the instructions say, and make a big sign and put it in the truck so I won't burn things down on the first try. It's so you can see which way the needle moves. It should move to discharge. It says if it goes in the opposite direction to switch the wires, of course AFTER taking the NEG. battery cable off.

Heck, before I move to install any of this wiring I'm disconnecting the battery.
I have been fiddling around back there behind the instrument panel with the battery hooked up. But I wasn't doing anything electrical yet either.

 

[DoubleDingo]

Sounds like you have a good direction to take. You got some solid advice.

That is crazy how the factory did that one connection. I know they show to splice wires by meshing the two ends of the exposed wires together, and soldering them, but yeah, that doesn't look soldered or meshed.

 

[Raider L]

@DoubleDingo,

Isn't that stupid crazy?! It's the only connection I have found on the entire truck that was like this. And I have redid the entire wiring from bumper to bumper. I untaped all the wiring front to back, cleaned every wire, soldered any wire that looked like it should have been, then covered all the wiring with the various sizes of conduit right down to the single #18 wire cioming from the fuel level sending unit in the tank. I wanted them all covered. You know they were all covered with that "friction tape" stuff that sticks to itself but it's not sticky tape, weird stuff.
I'm telling you, I was shocked yesterday when I finaly got it uncovered, to see what the heck was that lump that has been under that tape all this time. And like what, they were short so they grabbed a piece of light blue #10 wire to hook the Alt. to the link? What the heck?

And yeah, you are probably right, those fuses are 3 amp. in those little holders. I don't know how the factory amp gauge was hooked up on the printed circuit board because the gauges have "pins" that stick through the white plastic box behind the instrument panel. I used the schematic to locate all the wires after I removed the factory printed circuit and cut the gang plug off of it. Every wire that is going to all my aftermarket gauges are connected to a original wire that went to the gang plug, except the aftermarket Amp gauge. With that one I just attached the old Amp gauge black wire with white stripe to one post and a ground to the other post. Like I've said, the old gauge didn't work either. I hope I didn't fry my new Amp gauge and don't know it. I don't know, nothing ever happened to it, it never moved.

 

[Ellie Niner]

@Raider L It looks like there was a little solder on that connection, but somebody must have said "fʊck it" on the production line and just walked away half way through the process... or did someone else manage to bodge that up between 1974 and 1981? I have seen one or two things on my vehicles that look like they might have been done at gunpoint on the assembly line.

I think there would've been lots of smoke and carnage if that ammeter fried itself. Make double sure nothing on that circuit touches ground, and be sure the wiring going to and out of it is torqued down properly... and you should be good to go.

 

[DoubleDingo]

@DoubleDingo,

Isn't that stupid crazy?! It's the only connection I have found on the entire truck that was like this. And I have redid the entire wiring from bumper to bumper. I untaped all the wiring front to back, cleaned every wire, soldered any wire that looked like it should have been, then covered all the wiring with the various sizes of conduit right down to the single #18 wire cioming from the fuel level sending unit in the tank. I wanted them all covered. You know they were all covered with that "friction tape" stuff that sticks to itself but it's not sticky tape, weird stuff.
I'm telling you, I was shocked yesterday when I finaly got it uncovered, to see what the heck was that lump that has been under that tape all this time. And like what, they were short so they grabbed a piece of light blue #10 wire to hook the Alt. to the link? What the heck?

And yeah, you are probably right, those fuses are 3 amp. in those little holders. I don't know how the factory amp gauge was hooked up on the printed circuit board because the gauges have "pins" that stick through the white plastic box behind the instrument panel. I used the schematic to locate all the wires after I removed the factory printed circuit and cut the gang plug off of it. Every wire that is going to all my aftermarket gauges are connected to a original wire that went to the gang plug, except the aftermarket Amp gauge. With that one I just attached the old Amp gauge black wire with white stripe to one post and a ground to the other post. Like I've said, the old gauge didn't work either. I hope I didn't fry my new Amp gauge and don't know it. I don't know, nothing ever happened to it, it never moved.

At least you will know ALL of the wiring will be taken care of after this is done. That little yellow connector, I have never seen one with the yellow cover for that small of gauge wire, only the red ones. I do have large gauge wire yellow connectors with that tiny hole for the small studs like you'd see on the ammeter. That is an oddball connector for sure, and you have quite the expansive collection of electrical goodies.

 

[Raider L]

@Ellie Niner,

Ha, ha, ha, ha!! That's the funniest thing. Yeah, at gun point, the union, "You'd better not stop this line waiting for the electrician to come solder one d*mn wire!!"

@DoubleDingo,

I've got just the yellow connector I just bought that has the size ring on it for the post on the Amp gauge. It's like a 10-32 size I think, maybe a little larger. And I've got a whole bag of those star washers.

I went to Lowe's tonight and bought enough of those long peg board hangers that are made with a little ball end on them and finished replacing all the rest of the one's on that peg board that had to short of a hanger on it. Now, they are all long so nothing is crammed on a hanger. I hated to see a hanger with stuff barely hanging on the end of the rod, then you try to get something off and that rubber tip hangs the thing up and half the stuff off the hangers next to it come off! Uhgg!

Well, I can't wait until tomorrow! My wife had a minor surgical thing today and I had to go pick her up. So I didn't want to be half way doing something and then miss the time to go get her. And you know how things are...if there could be a problem, there will be a problem. I don't forsee anything hanging me up though. But with electrics you never know.
I'm excited to get my Amp gauge working....finally! I guess it's what you end up doing about a thing and not so much how long you've let it go, that's important. I made up a work sheet of each step I'm going to take in getting the wiring done tomorrow. First thing, disconnect the battery!!!

 

[Raider L]

Go to "Exterior" to see what I got in today.