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Battery arc'd and shorted, is alternator now toast?


AlbatrossCafe

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Was driving home late Saturday night on a slight downhill when sparks starting erupting from my hood. The engine immediately cutoff and sparks were flying so far that they were coming out through my hood vents. I turned off the key and coasted to a pullout on the side of the road.

What I found is that whoever did the L28ET engine swap 14 years ago on this car slid a rubber insulator over copper connection on the positive battery lead. This had slid off over the year of my ownership and grounded to the inside fender. I covered the lead, drove the car home and put it on the battery charger. Charger showed it was at 60% until morning where it became 100%.

Now, I have the following issues:

  1. Headlights are so unbelievably dim (before and after charging battery). Even when cruising at RPMs, they are equivalent to a couple of 15 year old weak flashlights. Not bright enough to drive without streetlights IMO
  2. Fan at speed 4 is more like fan at speed 2 unless I give it gas
  3. I turned off all electronics except flashers. At idle and with RPMs, it seems to sap a ton of voltage.
  4. Also, with just flashers on, there is a "honk" or "beep" that occurs when the voltage jumps to like 16? I have never heard that before. It is that a "charging indicator" or something? (see video below)

 

Could this have ruined my OEM 60amp alternator?

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did you test the voltage at the battery with the engine off and then again with the engine running?

nevermind I just watched the video. could be the alt or the voltage regulator. Maybe even the battery was damaged.

Edited by Dave WM
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1 hour ago, AlbatrossCafe said:
  1. Fan at speed 4 is more like fan at speed 2 unless I give it gas
  2. I turned off all electronics except flashers. At idle and with RPMs, it seems to sap a ton of voltage.
  3. Also, with just flashers on, there is a "honk" or "beep" that occurs when the voltage jumps to like 16? I have never heard that before. It is that a "charging indicator" or something? (see video below)

Could this have ruined my OEM 60amp alternator?

Can't tell if you have an external regulator or internal.  Or an ammeter or voltmeter.  But, voltage should not jump to 16, ever.  So, your regulator is shot, wherever it is.

Don't know what you have in the car that beeps so hard to say on that.  But whatever it is it probably wasn't designed for 16 volts.  I'd fix that regulator first and see where you're at.

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36 minutes ago, Zed Head said:

Can't tell if you have an external regulator or internal.  Or an ammeter or voltmeter.  But, voltage should not jump to 16, ever.  So, your regulator is shot, wherever it is.

Don't know what you have in the car that beeps so hard to say on that.  But whatever it is it probably wasn't designed for 16 volts.  I'd fix that regulator first and see where you're at.

I don't know either. Where would the external one be if I had it? Otherwise, it seems like Internal is attached to the alternator somewhere? (I think the below pics are what I should be looking for in regards to External vs. Internal)

Sry, I am new to engines and am still trying to figure out where everything is.

image.png

800-1282-Voltage-Regulator.jpg

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1 minute ago, rcb280z said:

If Your Z is a 78 then you should have an internal (in the alt.) regulator. 

Just saw that in his profile.  One other possibility is that the S(ense) wire burned off when the positive cable shorted.  There are unknown wires attached there.

Check S at the alternator plug for battery voltage.  Check fusible links also.  It will be fun.  Get a meter.

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11 minutes ago, rcb280z said:

If Your Z is a 78 then you should have an internal (in the alt.) regulator. 

 

5 minutes ago, Zed Head said:

Just saw that in his profile.  One other possibility is that the S(ense) wire burned off when the positive cable shorted.  There are unknown wires attached there.

Check S at the alternator plug for battery voltage.  Check fusible links also.  It will be fun.  Get a meter.

It is a '78 but it has an L28ET from an '82. Not sure what they moved over. I know the alternator is 60amp but that is it. I'll check voltage this week.

I know I was looking at getting a bigger alternator anyway (for electric fans) so if it is internal, a new alt would include a new regulator with it, correct?

Edited by AlbatrossCafe
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3 hours ago, Zed Head said:

It will be fun.

Yes, for you electrical guru's. I know just enough to get myself in trouble.

 

3 hours ago, AlbatrossCafe said:

Not sure what they moved over

I would say it is the original alternator. There would be no reason to go backwards.

 

3 hours ago, AlbatrossCafe said:

a new alt would include a new regulator with it, correct?

Yes (in it)

Edited by rcb280z
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Here are the problems I have noticed since I this arc:

  1. Tachometer dances all over the place when I push in the clutch (before it was very smooth/accurate)
  2. Speedo bounces a bit too
  3. Parking "Brake" indicator always illuminated
  4. Door chime sounding at double its normal speed
  5. Coolant temp pegged at max (250 degrees) while driving, but goes back to center after ~15 seconds of idling?
  6. Oil pressure pegged at max while driving, but goes back to center after ~15 seconds of idling?
  7. Voltage indicator at 16+ while driving with "Charge Light" always on
  8. Headlights are so dim they are unusable (even with Voltage at 16+)

Do you guys think that my ECU or some relays or something could have been affected as well? Not sure where a lot of these signals (speedo, tach, temp) come from or whether or not they go through ECU. Or are all these a byproduct of bad alternator and/or over-voltage?

Luckily I have a new 125A alternator from ZSpecialties and MegaSquirt 2 on the way. I hope that solves these issues.

 

74C8EX6.jpg

Edited by AlbatrossCafe
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On 9/17/2018 at 11:11 AM, Zed Head said:

 But, voltage should not jump to 16, ever.  So, your regulator is shot, wherever it is.

  But whatever it is it probably wasn't designed for 16 volts.  I'd fix that regulator first and see where you're at.

Thought that "don"t run the engine with the bad parts in it" would come through the comments, but, just in case...don't run the engine with the bad parts.  Actual voltage is probably higher if you're just reading the highest number on the gauge.  You might be damaging more stuff. 

And the speedometer is mechanical. So any twitchiness there is not from an electrical problem.  

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