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Discussion Starter #1
I foolishly reverse wired the battery last night and fried the alternator, possibly the starter and caused who knows how many electrical issues. Just wondering if anyone has made the same dumb move and could assist in diagnosing the problems I caused. my only consolation is none of the fuses blew and the car turned over for me once with working headlights and so on. I'm fairly certain I only killed the charging system but am convinced it created a short somewhere in the wiring because the headlights failed to work about 15 minutes after turning over the engine (whereas they burned bright after turning the car off). The battery still has 12 volts (checked with a multimeter) but I have no power throughout the car. Any advice would be hugely appreciated.
 

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I would first check all the fuses under the hood and in the car. (the knee bolster under the steering column) Hope you get it figured out.
 

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If you've fried the alternator then your just driving around on the battery only. It would only make sense the lights are going to dim as you drive, and then be brighter after the car is turned off.
I would use a voltmeter to the battery and measure the voltage before and after starting, you're looking for a significant increase after starting.
 

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Discussion Starter #4
to Rukee:

I started the car once after doing the damage to (at minimum) the alternator. lights worked then and after turning off the car. then let the car sit about 15 minutes and tried again. starter fluttered (click click click) and after that, lost all power. headlight's don't work at all, no dash warning lights...nothing. Checked the battery with a multimeter and I have voltage. Brought it to the local auto shop and it's at a 95% charge. so there's power in the battery that was able to run through the ignition/charging system...but with no blown fuses i'm not sure what to think. couldn't have grounded without a blown fuse.
 

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Discussion Starter #6
::: UPDATE ::: new electrical gremlin

::: UPDATE :::

I replaced the alternator tonight which has raised a new issue. After connecting the battery (correctly!) I tried my lights which worked along with the dash oil pressure and alternator warning lights. Everything was fine until I turned the key at which point the car lost all power once again. I disconnected and re-connected the battery and immediately had lights back. My only thought is there is a short in the starter solenoid. Once again, no blown fuses...anyone have any other suggestions?
 

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Have you checked your main fuse yet? Pull every fuse in the panels both below the knee bolster and under the hood, you may have quite a few blown, especially under the hood. I am not sure if they use fusible links anymore, but that is what they used years ago to prevent damage like this. If so they will need replaced,and are normally in the power wires at the starter, maybe explaining the starter trouble. Starters are pretty tough, should be fine unless you left it hooked up for a while backwards.
 

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Discussion Starter #8
it's a 1968, to my knowledge there are no fuses under the hood, just the panel against the firewall on the drivers side. As I mentioned before, there are no blown fuses. What's this "fusible link" you're talking about?
 

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The fusible link is on the positive battery cable connected to and coming from the starter main battery wire. It looks just like a regular wire, but it has a fuse inside of the jacket. If the 'fuse' burns, you may or may not see the rubber jacket burned. There are two smaller wires coming from the starter, it should be the red or 'not the purple' wire (which turns the starter 'on' with the key) coming from the starter. Best to use a test light at the main solenoid connection and then about 6" up that smaller wire attached there. If the fusible link is blown, you'll have no voltage up that second smaller wire coming back up that tube with the battery wire. Check for battery voltage when the lights go off, check the ground for a good ground at the motor and at the core support also when the lights are off. Clean the cable ends at the battery.
 

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Discussion Starter #10
Alright, so now that I know what the fusible link is I'm fairly confident it can be ruled out. If it were burnt out I wouldn't have a closed circuit, but my multimeter prooves I do. Also, I was able to successfully start the car once after toasting the alternator. If the fusibile link provides power to the starter, and it worked at that point in time...and works now to at least activate the solenoid, it's can't be an incomplete circuit. This all goes out the window if reversing the battery created a short somewhere in the system...
 

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Discussion Starter #11
to 6qts110z,

there were sparks and smoke when the battery terminals were reversed, that's what fried the alternator diodes and who knows what else. i was able to turn the car over once after correcting the battery properly. I didn't try to turn the car over or close any switches with the battery backwards. To reiterate, the alternator cooked, I properly installed the battery, the car ran (once) and now i'm having problems with losing all power whenever it turn the key past the power stop to activate the starter. Again, it is only at that point that I lose power to the car.
 

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There are no computers or anything to fry on a `68. If reconnecting the battery gets your lights back, again I would be looking at the battery connection and the ground wires.
it's not the power at the solenoid you're checking, it's voltage coming out of that smaller red wire coming from the solenoid. Just cause the solenoid has power doesn't meen that fusable link is good. You have to check 8-10" down that smaller red wire for power.
 

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Discussion Starter #14
Rukee:

Should I be testing the positive lead to the starter before or after turning the ignition and losing power? I'm just not sure if you mean voltage or continuity. A test light (or tone in my case) will let me know if the fusible link it's burnt without putting a charge through the wire. The Ground is good and clean, just couldn't get under the car to check the starter's positive lead last night.
 

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to 6qts110z,

there were sparks and smoke when the battery terminals were reversed, that's what fried the alternator diodes and who knows what else. i was able to turn the car over once after correcting the battery properly. I didn't try to turn the car over or close any switches with the battery backwards. To reiterate, the alternator cooked, I properly installed the battery, the car ran (once) and now i'm having problems with losing all power whenever it turn the key past the power stop to activate the starter. Again, it is only at that point that I lose power to the car.
Gotcha! I would replace the battery especially if it wasn't new. Just because a battery has voltage doesn't necessarily mean that it has the proper amperage (cold cranking amps). I think the battery itself is history. You probably just got lucky and shorted out the alternator as well as the battery. That's probably why no fusible link or fuses blew due to excessive current (amperage). Just a thought.
 

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I'm more of a hands on troubleshooter than anything else so I do the best I can in the short amout of time I have. By skimming through the thread I noticed a few things. Your starter works(because it clicked and you was able to start it), new altinator, everything lights up after the fact that you wired the battery wrong, correct? That means all your fuses are good and you don't have a break in the system. But it sounds like your still using the same battery. The next thing I would do is jump the car or replace the battery. Try this: take off your negitive terminal and reconnect it, does it have massive spark? A small, little spark is fine, big spark means you have a short somewhere or you have current draw. Also if you have an muiltmeter have someone check the battery voltage while you trying to start it, see how much it drops. You can't check amps unless you have the multimeter hooked in parallel(don't try it). You may have one on the dash, if the car is running it should be all the way on the positive side, if on the negitve you will have a current draw, and the altnator not working. The car is running with a voltmeter then you should be reading 13.2-14.5 volt-ish.
 

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Discussion Starter #17
To Everyone:

Thanks for your help and suggestions. When I finally got underneath the car it turned out that my only problem was a loose solenoid connection. Very happy to be out cruising with the top down once again.
 
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