Alt Light addition

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jwgreen

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Hey guys, I want to add an Alt light to my truck but it didn't come with one. I understand how to wire it in but I was wondering if there was a replacement graphic that I could switch out in the dash where either the 4X4 or CHOKE light is in the gauge?
 

Ricko1966

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Does the truck have a working gauge? I ask because Volkswagen use to use a buzzer underdash when the buzzer went off it was to notify you to look at your gauges. Lots of people use to do the same with buggies a buzzer for oil pressure and a buzzer for charging. I do not know your goal,just throwing that out there. It's a real easy install.
 
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jwgreen

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Does the truck have a working gauge? I ask because Volkswagen use to use a buzzer underpass when the buzzer went off it was to notify you to look at your gauges. Lots of people use to do the same with buggies a buzzer for oil pressure and a buzzer for charging. I do not know your goal,just throwing that out there. It's a real easy install.
Ricko, Yes has a working gauge but was just wanting to add and idiot light as my brother doesn't pay attention to anything. I hooked up a buzzer for the headlights so that he won't leave them on but was just wanting a clean neat looking light for the alt. Didn't know if anyone out there made them as I couldn't find them with a google search. Thanks for your reply.
 

75gmck25

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I really don't see how an alternator light will save you from your brother's issues with not paying attention.. Poor charging on the alternator is a minor problem compared to low oil pressure or an overheating engine, and there are no idiot lights for those issues if you have a truck with gauges.
 

Raider L

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@jwgreen
I had the light when my dash was stock. The light is part of the integrated circuit board. In the gang plug in the back of your instrument panel will be a #24 brown wire coming into the gang plug from the bulkhead block behind the fuse panel. On the other side of the bulkhead block where all the wires come together to go inside the truck is a #16 brown wire that comes from your Alternator, if you had a two (2) wire alt. In the dash on the printed circuit is a light bulb the #24 wire feeds a 12volt signal from the alternator. As soon as you start your truck a red light (because of a red plastic lens in front of the light bulb) would come on then after a couple of seconds would go off if your system was in good working order. That light would get a signal from the field winding's in the alt. and as soon as the winding's were energized that light would go off. If it didn't come on you had a alt. problem. If it stayed on you had a alt. problem. If it kept going off and on or flickered or was weak, you had a alt. problem. So that little light is important.
I need to restore it back in my truck as I cut it out when I rebuilt my truck not knowing what I was doing. It didn't seem to matter much and didn't cause me a problem so I left it out. Now I want it back, especially if it would keep me from having the problem I'm having now.
 

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Maybe use the idiot lite to activate an upwards facing seat mounted taser. To get his attention.
 

Raider L

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@jwgreen,

Did you ever hook up your alt. light? Do you have a one wire alternator or a three wire alternator. I just hooked up the light for mine, but I don't have a printed circuit in my truck anymore everything is hard wired. For one thing if you have a three wire alt. it's the #16 brown (or tan) wire with the #12 white wire in the plug in the alt., it's the #1 wire in the plug. Then that goes in the cab and attaches to the gang plug in the back of your printed circuit at #25 position in the plug, check the schematic. From there the alt. just sends it's signal to the light at startup. Oh yeah, I forgot to ask, what year truck do you have? Is it the '85 C2500? Your alt. light for your year truck may not be at #25, yours might be in another location and for a C2500 probably is. If you don't have the light it may be because someone cut it at some time for something else they did.
And what gauge is it that you say you have?
 

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This is an option.


Basically, the way the warning light works on a GM car is:

Power is supplied to one side of the warning light from the pink/black tracer wire powered from the Gauges fuse. The other side of the light is connected to the brown wire at the alternator. The alternator supplied power on the brown wire while the alternator is charging, the bulb is powered on the other side by the gauges fuse. Power on both side, bulb doesn’t light. If the alternator stops charging, the regulator is designed to supply a ground to the bulb, causing it to turn on.

Hope that helps.
 

Raider L

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@Matt69olds,
Okay! That does make sense. I don't know if my gauge has a "fuse", but as I discovered watching a video was the guy was attaching the other wire, not the alt. wire, but the other wire to 12v. And in my situation it is the same as what you were saying that the 12v is coming through the gauge fuse. And that would be right, that if something goes wrong in the voltage reg. it goes to ground and the light comes on. That was what I observed when I had the "other wire" of the alt. light hooked to the ground post on a gauge near by for convenience and when I cranked the engine like that, the light came on and stayed on. So I watched the video again and that's when I noticed the guy attached it to 12v, and that's when it made sense for it to be that way. So I switched the other wire to the 12v post on that near by gauge and cranked the truck again and it worked perfect.
In the pic below the alternator light is to the right center of photo, just in front of the gauge with the white housing. You'll see at that light, (black bulb housing up against back of instrument panel), red shrink wrap on the alt. wire, and black shrink wrap on the other wire. And if you follow the black wire on the light housing it goes to the post on the near by gauge with a red wire on it. I know it looks kinda jammed up right there but there is just enough room for the ring terminals. That red wire is on a 12v keyed ignition.
I guess looking at all the wires I have is the reason why GM came up with a printed circuit with a gang plug in the back that carries all the wires to one point. Just think, this is how it used to be, wires going everywhere. I know it looks bad but I have a lot of wires piggy backed to the back of the gauges in order to keep from having twice as many wires everywhere!
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Matt69olds

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The alternator light is powered by the gauges fuse in the factory fuse box.

I know all too well the hassles of custom wiring. When I first started playing around with cars, I use to run wiring without any thought of how I would service things later. The ability to remove and disconnect something and get it out of the way makes things MUCH easier.

I have lots of things in my cars and trucks wired with connectors like this. If you have a Pick a Part nearby, connectors like this are cheap. The terminals do take special tools to remove, and special crimpers, but are well worth the money.
 

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Raider L

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@Matt69olds,
Thanks loads! Talking about those special tools to install/remove the terminal ends in the connectors, I need to buy the whole set. The terminal ends in the plugs in my '74 are these weird hooked looking things inside the plug. It's impossible to get the end out unless you have the correct tool otherwise.
 

Matt69olds

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Pretty sure this is the tool kit I bought.

JRready ST5211 Pin Removal Tool KIT for Weather Pack Metri Pack Series Connector Harness terminals and Connector Crimp pin etc Electrical Connector, Tool KIT Include DRK 785084 Amp 1.5mm Removal Tool https://a.co/d/6eanl3x

I think every square body uses series 56 terminals. You can take an old pocket screwdriver to remove the male terminal, you basically bend the locking tab making the terminal narrower. Once it’s removed straighten the terminal. You will probably need to grind a pocket screwdriver to fit the female locking tab.
 

jwgreen

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@jwgreen,

Did you ever hook up your alt. light? Do you have a one wire alternator or a three wire alternator. I just hooked up the light for mine, but I don't have a printed circuit in my truck anymore everything is hard wired. For one thing if you have a three wire alt. it's the #16 brown (or tan) wire with the #12 white wire in the plug in the alt., it's the #1 wire in the plug. Then that goes in the cab and attaches to the gang plug in the back of your printed circuit at #25 position in the plug, check the schematic. From there the alt. just sends it's signal to the light at startup. Oh yeah, I forgot to ask, what year truck do you have? Is it the '85 C2500? Your alt. light for your year truck may not be at #25, yours might be in another location and for a C2500 probably is. If you don't have the light it may be because someone cut it at some time for something else they did.
And what gauge is it that you say you have?
Raider L, I never did get this hooked up as I was limited on time and wasn't certain how to make it work correctly. Also I was really hoping to replace one of the lenses for the 4X4 or Choke for a ALT and/or TEMP lense as to not have to "add" a light somewhere. But it seems no one makes these lenses or can make a custom one. But I will install some sort of light later when I have more time to mess with his truck.
 

Raider L

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@Matt69olds,
Would you know where I could find terminal end boots for a 3/8" nut? I emphasize the "nut" because I found in searching for the boots they measure the ends in different ways and I tried to call them what they were calling them and that led nowhere, to cover those nuts on the back of the Amp. gauge. There's so much current going to those things. I found out the hard way when I blew up another amp. gauge I had just put in and another gauge's light socket accidentally popped over to those contacts while I was fiddling back behind the gauge's, and a huge spark and smoke came off the nuts on the back of the amp gauge just when I was about to test the gauge. I've found a couple of covers on line but they want so dang much for these two little rubber things, then they wanted my left leg in shipping and handling that I couldn't touch them.
Just two cheap rubber boots, covers, whatever you want to call them, to cover up those nuts on the back of the amp. gauge. Got any idea where I could find some cheap ones?

The pic below are two of some that I have. The one on the right is the size I need, it IS for a 3/8" nut, and probabl7y a #10 wire, or a #12. The one on the left measures 9/16" on the end that fits over the nut, or in these case it would probably be a nut on a bolt it's so big.
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In this photo below you can clearly see the size of the end the wire would go in. The one on the right is actually a bit small, or I might be able to slick it up and push it over the terminal end of that #10 wire. The only problem is I only have one of these. Of course. When you really need something, you dig and dig and you always come up one short.
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Below you can clearly see in the one on the right, the 3/8" one, that there is a sort of a cavity where the nut would be. That's okay, so long as it's not to loose in there. But this is what I need. I can't believe how much people want for these things.
Would you know of any electrical supply sites on line. All the electrical supply places in my town don't have anything this small. And where is Radio Shack when you need them. And, yes, I did try Radio Shack on line. No luck. Of course here locally they only carry stuff so that if you were building a subdivision full of town houses they'd have all the electrical supplies you need. But if all you need is two 3/8" terminal covers...forget it!
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