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Discussion Starter #1 (Edited)
Well I went out and ran the GT today.
After I started it and it ran for a minute I noticed an arc flash under the dash at the fuse box. Then it died. Now when I turn on the key there is no power to the dash or anything else. The battery is fully charged and looking at the fuse block there are no fuses blown. Where do I start to figure out what the problem is?
 

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Opel Key Master
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Hard to tell on my phone, but looks like the jumper wire to the headlight relay, if it’s large white wire. Think I was using white for the yellow and white wire back then. Unhook battery and check wires, insulate them if for some reason they are bare. Possible a voltage regulator is bad and running too much voltage out. I would check with a test light that you have power at all 4 studs in the center of the fuse box, if not, that’s where to start. A lot of times when the fuse box shorts, these get hot and lose connection. Also could be an ammeter
 

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Just Some Dude in Jersey
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You need a volt meter. Test various fuse points on the fuse box looking for 12 volt power with the key off. Note where you find power. Turn the key to the Run position and look for power again. All or almost all the power in the car runs through the Ampmeter check the wires leading to that. Here's the wiring schematic for the whole car. Especially check for power at the RED wires to begin the process.

GT wiring schematic.jpg
 

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Discussion Starter #7
I have 12 volts to the starter. I'll start checking the fuse block next. Does someone have a good picture of the fuse block that they could post and I'll check each of the terminals and get back to everyone. Thanks
 

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Discussion Starter #8
One other thing I did notice when I was running it. The AMP meter was swinging pretty wildly before it arced at the fuse box. Do you think it might be the voltage regulator doing that.
 

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Opel Key Master
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Could be, I can’t remember what alternator we used on that. A test light will be a quick way to see where you have power and where you don’t. Check the 4 posts first. They are the threaded studs on your fuse box picture. The starter will have power because it is directly hooked up to the battery.
 

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Opel Key Master
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You should have power at the stud next to it too, that wire goes to the ammeter. A quick fix would be to jump these two studs together. It looks a little melted between the studs there, what happens is it gets hot and melts the plastic, then looses connection to the other stud. I am a little surprised that maybe the fusible link didn’t blow, but I had a voltage regulator put out 17volts on a GT once and would spark at the fuse box and blow any light that was on
 

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Discussion Starter #12
You should have power at the stud next to it too, that wire goes to the ammeter. A quick fix would be to jump these two studs together. It looks a little melted between the studs there, what happens is it gets hot and melts the plastic, then looses connection to the other stud. I am a little surprised that maybe the fusible link didn’t blow, but I had a voltage regulator put out 17volts on a GT once and would spark at the fuse box and blow any light that was on
Where is the fusible link? I'll try jumping across them tomorrow. Do you know where I can get a new fuse box?
 

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Opel Key Master
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Just get ready to act quickly if running it again by jumping the studs side by side. What I mean is the stud that has the red/white wire that has power, Jump it to the other red/white stud. Then you should get power on the other two studs with the key off. If that is the case, you should be able to start it now, but if the problem is still there, it might arc again. We’re you running the lights when this happened? If not, then I would look at what alternator is on it. If it is a stock one, then the voltage regulator is separate. If I put a GM unit on it, might disconnect the power wire and insulate it before starting. It’s trial and error now
 

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Discussion Starter #15
I was not running the lights when it happened. It has a separate voltage regulator. I believe the alternator came from OGTS but not sure which one.
 

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Opel Key Master
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Looking at the second fuse box picture on an iPad, I can see where the red/white studs are burnt up, or that is where it arced. See if on the white wire the black marks simply wipe off. You have lost connection at those two studs, they have a buss bar that links them together. So if you reconnect those, the car will have life again, but now you still have to figure out what caused the short or the studs to get hot. I had a customer hook up a battery backwards one time and did this almost to the tee. Was the battery low on power and working the alternator hard? Voltage regulator? That’s where I would be looking
 

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Discussion Starter #17
The black wiped off the white wire. Soot. The battery was fully charged over night on a trickle charger. When it arced I notice just prior the alternator gauge was spastically pinging back and forth.
 

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Just Some Dude in Jersey
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Here's a few of the system specific wiring diagrams from the FSM. Rather than getting overwhelmed by the enormity and interconnectedness of the whole car's wiring system, you can use these diagrams to just trace power in a specific subsystem. Often, this will lead to finding the problem that is affecting all the other subsystems:

Alternator wiring 001.JPG Engine compartment wiring.JPG GT FSM starting-charging-ignition system.jpg headlight wiring 001.jpg Ignition switched circuit 001.JPG

When I had a stock fuse box I would first start by making sure that all the colored connectors on the fuse box are plugged in all the way. You also have two halves to the system: Unswitched power and switched power(ignition switch). If none of the stuff that only comes on when the key is in the Run position work, then you know that you probably have lost power to the ignition switch. That rules out a whole bunch of stuff and narrows your search.

:veryhappy
 
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