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Electric Charge on AC Lines?

Old Apr 25, 2017 | 06:36 AM
  #31  
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It's possible that would solve the immediate symptom of measurable voltage on the tube, but would not solve the root problem. That voltage should not have gotten there in the first place.

Also, you'd have a nasty battery drain, too.
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Old Apr 25, 2017 | 11:29 AM
  #32  
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OK, now I am truly confused.

I did a bunch of troubleshooting, disconnecting everything off the positive side of the battery one at a time, until I finally just disconnected the positive battery terminal entirely.

Still could get a charge from AC line to neg. terminal.

So I finally disconnected both sides of the battery. Now the battery is totally disconnected.

I can STILL get the .5 volts from AC line to the ground point on the inner fender (where the neg battery ground screws in). I pulled the screw out of that ground point, and put the multimeter from the fender ground point to the AC line and the charge remains.

What the heck? Any ideas?
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Old Apr 25, 2017 | 11:41 AM
  #33  
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Originally Posted by mtyson
OK, now I am truly confused.

I did a bunch of troubleshooting, disconnecting everything off the positive side of the battery one at a time, until I finally just disconnected the positive battery terminal entirely.

Still could get a charge from AC line to neg. terminal.

So I finally disconnected both sides of the battery. Now the battery is totally disconnected.

I can STILL get the .5 volts from AC line to the ground point on the inner fender (where the neg battery ground screws in). I pulled the screw out of that ground point, and put the multimeter from the fender ground point to the AC line and the charge remains.

What the heck? Any ideas?

Use a different meter.
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Old Apr 25, 2017 | 03:34 PM
  #34  
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Originally Posted by CCKen
Use a different meter.

maybe its on ohms!

Last edited by nujeepguy; Apr 25, 2017 at 08:03 PM.
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Old Apr 25, 2017 | 07:25 PM
  #35  
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whoa. It is highly unlikely, damn near impossible, to feel 12vdc (nominal) through dry skin. Just doesn't happen. Therefore you are left with a couple of possibilities: 1-the vehicle somehow made contact w/line ac voltage (that is, utility power, like 120vac or higher), 2-the secondary side of the ignition system, that is the spark plug wire(s), plugs, etc have an insulation issue that is allowing the secondary voltage to shock your friend (only if engine running) or 3-static charge. Stop wasting your time trying to find an issue with the 12 volt system, its not the source of your shock.
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Old Apr 25, 2017 | 08:03 PM
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Originally Posted by Charlie Foxtrot
whoa. It is highly unlikely, damn near impossible, to feel 12vdc (nominal) through dry skin. Just doesn't happen. Therefore you are left with a couple of possibilities: 1-the vehicle somehow made contact w/line ac voltage (that is, utility power, like 120vac or higher), 2-the secondary side of the ignition system, that is the spark plug wire(s), plugs, etc have an insulation issue that is allowing the secondary voltage to shock your friend (only if engine running) or 3-static charge. Stop wasting your time trying to find an issue with the 12 volt system, its not the source of your shock.
i said that basically a few ways and was laughed out!,told not to comment on electricity so thanks . maybe they will give up this wild goose chase! you note that the compressor lines are solidly grounded huh.
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Old Apr 25, 2017 | 08:21 PM
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Originally Posted by CCKen
Use a different meter.

I think Ken nailed it.
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Old Apr 26, 2017 | 10:44 AM
  #38  
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Originally Posted by mtyson
I mentioned this in another post, but wanted to specifically see if anyone has ideas.

My buddy had his hands on the AC lines when the driver door was shut and felt an electric shock go into his hands (he's mechanical, not inclined to imagine such things).

What could I check to try to run this down? Any leads at all?

Thanks everyone.

Diazepam?


Seriously, if the motor was running and a spark plug wire touching some part of an AC line, that'll do it.

Last edited by Knucklebuster; Apr 26, 2017 at 10:46 AM. Reason: second thought
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Old Apr 26, 2017 | 11:09 AM
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Electrolysis from your radiator?
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Old Apr 26, 2017 | 11:11 AM
  #40  
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http://www.ve-labs.net/electrolysis-101
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Old Apr 26, 2017 | 03:38 PM
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Originally Posted by Knucklebuster
Diazepam?


Seriously, if the motor was running and a spark plug wire touching some part of an AC line, that'll do it.
we wonder how you get "shockable" volts on grounded tubing on the compressor. the entire air system is grounded like all other metal
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Old Apr 26, 2017 | 04:52 PM
  #42  
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Yes yes, I too had the same thoughts occur to me before I posted my last, ie: I've lost my mind or the meter is bad.

Therefore, I went to AZ and got a different meter. You'll just have to trust me on the first score.

The new meter shows the same readings. I know.

Incidentally, when Casey felt the charge on the line, it wasn't "Oh my God I'm being electrocuted", it was more "Huh, that's weird I just felt some current in the palm of my hand". Sweaty palm perhaps?

Moving on, since I am nothing if not persistent, my question now becomes: where does this AC hard-line go into behind the dash area? Do I need to remove the airbag panel to access?

I have had the battery disconnected for about an hour, is the airbag going to deploy/decapitate?

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Old Apr 26, 2017 | 06:29 PM
  #43  
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Originally Posted by mtyson
OK, now I am truly confused.

I did a bunch of troubleshooting, disconnecting everything off the positive side of the battery one at a time, until I finally just disconnected the positive battery terminal entirely.

Still could get a charge from AC line to neg. terminal.

So I finally disconnected both sides of the battery. Now the battery is totally disconnected.

I can STILL get the .5 volts from AC line to the ground point on the inner fender (where the neg battery ground screws in). I pulled the screw out of that ground point, and put the multimeter from the fender ground point to the AC line and the charge remains.

What the heck? Any ideas?
Its magic...
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Old Apr 26, 2017 | 09:21 PM
  #44  
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what do you read with meter leads shorted,and what range are you on?
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Old Apr 27, 2017 | 08:25 PM
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Originally Posted by mtyson
Incidentally, when Casey felt the charge on the line, it wasn't "Oh my God I'm being electrocuted", it was more "Huh, that's weird I just felt some current in the palm of my hand". Sweaty palm perhaps?
I have gotten a nasty jolt from getting my sweaty hand between the fuse box and a good ground while working under the dash of a car. I'm just having trouble with the idea of feeling such a low voltage.

Although, it's possible it was the full 12v when he felt it.

I think you are on the right track looking under the dash, but I have no idea of the routing back there.


Originally Posted by mtyson
I have had the battery disconnected for about an hour, is the airbag going to deploy/decapitate?
Nope. No problem there.
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