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87 Fusebox power wire

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Old Apr 23, 2026 | 04:41 PM
  #1  
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Car: 1987 Trans Am
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87 Fusebox power wire

Does anyone know where the battery power plugs into the fusebox?
Car was gutted so I cant just follow a wire from the starter.
I dont see anywhere clear where it could go in and I’ve already tried a couple different places that didnt work.
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Old Apr 23, 2026 | 04:47 PM
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Re: 87 Fusebox power wire

Not sure what you're asking.

Battery power doesn't "plug into" the fusebox. It's kinda crimped onto a big metal strip piece on the back side, that then goes under one end of each of several fuses.

Look for a Big Red Wire on the back of it. There might even be 2 such wires (since there's 2 batt feeds into the cabin), although the batt stuff that's powered via the fusebox doesn't amount to very much load, and so can all be accommodated, electrically, off of just 1 of The Big Red Wires. Most of the load that The Big Red Wires see follows other paths than through the fusebox, such as through the ignition switch, headlight switch, to power accessories such as seats window mirrors etc., and so on.
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Old Apr 23, 2026 | 04:58 PM
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Re: 87 Fusebox power wire

Originally Posted by sofakingdom
Not sure what you're asking.

Battery power doesn't "plug into" the fusebox. It's kinda crimped onto a big metal strip piece on the back side, that then goes under one end of each of several fuses.

Look for a Big Red Wire on the back of it. There might even be 2 such wires (since there's 2 batt feeds into the cabin), although the batt stuff that's powered via the fusebox doesn't amount to very much load, and so can all be accommodated, electrically, off of just 1 of The Big Red Wires. Most of the load that The Big Red Wires see follows other paths than through the fusebox, such as through the ignition switch, headlight switch, to power accessories such as seats window mirrors etc., and so on.
I assumed there would be a stud it bolts to or a port on the back it plugs into. There is no big red wire, the only thicker gauge red wire i have is plugged into to tailight fuse, so I assume thats the tailight power wire.
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Old Apr 23, 2026 | 05:10 PM
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Re: 87 Fusebox power wire

I assumed
:smh:

There's a Big Red Wire SOMEWHERE. You can be sure of THAT. [/mr_filch] Battery couldn't get there any other way.

the only thicker gauge red wire i have is plugged into to tailight fuse
When you looked at the back of the fusebox, and found the metal strip thing built into the fusebox that carries batt to all the fuses that this particular Big Red Wire supplies battery to (TLs, CTSY which is interior lights & cig ltr & radio memory, & brake lights), and followed that strip thing to all those fuses, didn't that answer your question?

"Gutted" is kinda a "relative" term. (not that we should do that to our relatives, at least, not all of em) Just how "gutted" is this car?
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Old Apr 23, 2026 | 05:38 PM
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Car: 1987 Trans Am
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Re: 87 Fusebox power wire

Originally Posted by sofakingdom
:smh:

There's a Big Red Wire SOMEWHERE. You can be sure of THAT. [/mr_filch] Battery couldn't get there any other way.



When you looked at the back of the fusebox, and found the metal strip thing built into the fusebox that carries batt to all the fuses that this particular Big Red Wire supplies battery to (TLs, CTSY which is interior lights & cig ltr & radio memory, & brake lights), and followed that strip thing to all those fuses, didn't that answer your question?

"Gutted" is kinda a "relative" term. (not that we should do that to our relatives, at least, not all of em) Just how "gutted" is this car?
it has no wires whatsoever from the starter, or the batt everything else is self explanatory so i can wire it easily. I have no tried every single big red wire going into the fusebox, one went to only the hazards, and the other went to the door lights
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Old Apr 23, 2026 | 08:20 PM
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Re: 87 Fusebox power wire

The variety of different IPBEC (Instrument Panel Bussed Electrical Center) / Fuse Panels that are used in our Third-Gens typically have a couple of
Power Distribution Slots/ Power-Taps populated with Female Pack-Con III Terminals marked: "BAT", that will accept a Mating Male Terminal.

Shown in the Image below, circled in RED:


The "BAT" identification does NOT actually mean that a Direct Battery connection is present,
but in actuality it means that the corresponding Circuit is always Active/ ON.

Power in the above locations is provided through the 20A Power Accessory Fuse/ 20A Courtesy Fuse within the IPBEC.

The Circuit is as follows:
-Ground through the Negative Battery Cable to the Negative Battery Terminal.
-Positive Battery Terminal via Positive Battery Cable to Starter Motor Solenoid.
-Starter Motor Solenoid via Fusible-Link and 10AWG Cable to the C100 Firewall Bulkhead Connector.
-C100 Firewall Bulkhead Connector to the IPBEC 20A Fuse/ Buss-Rail and "BAT" Power Distribution Slots.



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Old Yesterday | 08:01 AM
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Re: 87 Fusebox power wire

Doesn't seem like you're listening.

Not completely sure about this "from the starter" business you keep speaking of... although as you can clearly see from vorteciroc's piece of a schematic, The Big Red Wire that you have found on your fusebox, is fed from one of the fusible links that connect to the battery at the big starter terminal. The Big Red Wire under the hood, wire #2 along the left side of the diagram up there, goes from that FL, to C100 (the big pass-through under the brake booster), then on the interior side of the firewall, meets a splice, from where it goes to several places, including the fusebox.

Also not completely sure what you're trying to "wire". If you have the fuesbox with a Big Red Wire on the back of it at/near the tail light fuse, then you've found what you need. All you have to do is hook the car back up: connect the fusible link at the starter, plug C100 back in, and you're done.

I notice that on that schematic, the Stop/Hazard fuse is not shown. Seems a bit mysterious to me butt w/e, what do I know anyway. You can see the fuse for it in his photo of a fusebox, with one of its terminals right there next to the other battery-fed loads, such that the metal strip thing with the Big Red Wire crimped to it, can connect to all of those fuses, within a short distance.

You can't power the car by plugging power INTO the fusebox somehow, if that's what you're trying to do. That's backwards. ALL power would then be forced to flow backwards through whichever one of those fuses, probably the ACC or CTSY one (the photo he posted doesn't have CTSY butt most do), which the fuse will simply blow when you try to use everything.

Not sure how this is hard to understand?

Last edited by sofakingdom; Yesterday at 08:06 AM.
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Old Yesterday | 10:32 AM
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Car: 1987 Trans Am
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Re: 87 Fusebox power wire

Originally Posted by sofakingdom
Doesn't seem like you're listening.

Not completely sure about this "from the starter" business you keep speaking of... although as you can clearly see from vorteciroc's piece of a schematic, The Big Red Wire that you have found on your fusebox, is fed from one of the fusible links that connect to the battery at the big starter terminal. The Big Red Wire under the hood, wire #2 along the left side of the diagram up there, goes from that FL, to C100 (the big pass-through under the brake booster), then on the interior side of the firewall, meets a splice, from where it goes to several places, including the fusebox.

Also not completely sure what you're trying to "wire". If you have the fuesbox with a Big Red Wire on the back of it at/near the tail light fuse, then you've found what you need. All you have to do is hook the car back up: connect the fusible link at the starter, plug C100 back in, and you're done.

I notice that on that schematic, the Stop/Hazard fuse is not shown. Seems a bit mysterious to me butt w/e, what do I know anyway. You can see the fuse for it in his photo of a fusebox, with one of its terminals right there next to the other battery-fed loads, such that the metal strip thing with the Big Red Wire crimped to it, can connect to all of those fuses, within a short distance.

You can't power the car by plugging power INTO the fusebox somehow, if that's what you're trying to do. That's backwards. ALL power would then be forced to flow backwards through whichever one of those fuses, probably the ACC or CTSY one (the photo he posted doesn't have CTSY butt most do), which the fuse will simply blow when you try to use everything.

Not sure how this is hard to understand?
I got it to work, it did in fact just plug in to the rear of the fusebox, I found from an old camaro diagram that one of the ports on the rear is for battery power, i put a male connector in there and now everything works perfectly including ignition switched circuits. Not sure if this is the normal way but it is what worked. This is what I meant by plugging in. The wire near the tailight fuse was not the correct wire nor were any of the other big red wires, as I said that power wire was not there at all, so I had to wire a new one.
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