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Discussion Starter #1
So sadly last night the car hydroplaned through a wet intersection while making s left turn and smacked me into the sidewalk (thankfully nothing else) But it smacked the negative terminal off and rubbed it against the fender causing the voltage to drop super low then went super high when i pushed the gas and the car just backfired and everything died. When i opened the hood after it died i finally saw the negative terminal had came off. And i saw that my electric fan fuse was toasted so i replaced that today and it works fine again, However i have 0 lights. No taillights, Brakes, Headlights, Interior lights, Nothing. Is there a fuse or something these all connect to together?
 

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Discussion Starter #2
On the LPS fuse I know it says 4A and oreilly only had 20A in that length so i just tried it. Does it have to be 4A? Would the 20A not work? I’m really new to electrical stuff so sorry
Also the ONLY light that’ll turn on is the passenger front side marker (I smacked it and it randomly turned on) And the front blinkers will turn on as a solid. But will flash in hazard mode but go into solid if you step on the break
 

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Typically, light fixtures ground out the the chassis so metal to metal contact between the light fixtures and the body ultimately create the path to back to the negative battery terminal.. If there were any ground wires or straps that got distributed when you hit the curb you may not have a clear path back to the battery. Your negative battery cable is connected to the battery and the engine block. There can be ground wires connected to the negative battery terminal going to the chassis as well as from the engine block to the chassis.. You’ll have to see if you are getting power to the light fixtures.. Use a continuity tester and start testing for power at the plugs. If you’re getting power to the light fixture terminals then it’s a ground path issue..
 

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You need to put the proper 4 amp fuse back in place. Check with different parts shops until you find the correct amperage and length. You can get away with using a higher amperage fuse for a quick fix, but the fuses are there to protect your wiring and, ultimately, your car. It's possible to have an electrical fire if you use a high amp fuse in a low amp circuit.

If Custom Jim jumps in, he'll be the best help. In the meantime, I'd suggest checking each load (lights and other things that pull amperage) for both ground and power. You can check ground with all the power and switches turned off - you just need a continuity tester or multi-tester. Set the mult-tester for Ohms or Resistance, put one probe on the ground wire for the load, and the other probe to a known good ground point on the chassis. You're looking for a beep on the continuity tester or 0 ohms/resistance on the multi-meter. Unfortunately, checking electrical problems is time-consuming. You need to check each junction (connector) along the route back to the fuse box, then the same wire and junctions back to the battery to make sure you have good ground the entire route. Then, you have to check the next load.

Do the same sort of thing for the positive wire on each load, but it has to be done with power and appropriate switches on. Also, you'll need a multi-tester set for DC voltage to test this. You're looking for around 12V.

All that said, I think you may save some time looking for a commonly shared wire or switch since you have so many things that went out at once. Start with the ground wire on the battery and make sure you've got a tight connection there. Go ahead and check battery positive while you're there. Then, trace the battery negative backwards and see if you find anything burned or loose along the way.

Another thing that may save you time is to check for power output on all the fuses. Maybe one is bad or loose and it isn't obvious.

I don't envy you the task. With the combination of possible water invasion and the big bang of hitting the curb, your problem could be anywhere.
 

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If you don't have ground straps between the engine and body/frame (like my car), check the small ground wire running from your ground cable by the battery to the fender. IIRC I solved a light issue by connecting this wire (removed fenders for quite a while and forgot about that wire).
 

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Discussion Starter #8
So i bought one of those circuit testers today and i checked all the fuses on the box and they all lit up, I then checked that saddle of wires for the lights and every wire would light up except for the top two wires (black and grey). And i even checked if there’s power at the headlights and it would light up so does that mean the headlights are getting power?
 

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Discussion Starter #9 (Edited)
So where i circled the two wires in red is where no power was detected, Does anyone know what those two wires go to?

And then in the second picture where i marked green it would detect power, While the other two that are red detected nothing

Also should i be able to detect power from the grounds? I’m assuming the grounds are the parts where the wires are bolted down on the body.
 

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If your test light illuminates when you test the plug at the head light fixture, you are indeed getting power to the headlights.. I suspect you lost a ground wire somewhere near the battery when the cable came loose in the impact.. Look for a stray wire in the engine bay near the battery.. The fenders, core support, subframe, and main body shell are all bolted together and should carry ground throughout, but 50 years of life and exposure to the elements can creat corrosion and make the connections between them less conductive..
 
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