| LED House Light Oddity [message #270701] |
Wed, 28 January 2015 22:26  |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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First of all, I did not get my LEDs from any of the vendors known to the GMC community. I suppose I should admit that I, with his permission, used some of my friend's LEDs that were sent to my house and waiting for his arrival. (The price, perhaps, for storing his coach out in the elements for three months.) I offer no solutions here and am only telling what happened and what I found.
I installed the LEDs in all my fixtures except the two reading lights in the bedroom. On a recent trip to and stay in Fort Bragg, CA, a house fuse blew out leaving half the lights working. It didn't take long to find the bad fuse and replace it. However I did wonder why a fuse was burned when the amperage for lighting should be much reduced.
The next day I noticed one side of the hall light was not working. Because I was generous to myself when I appropriated, with permission, the LEDs I installed a new unit. In doing so I noticed a tiny brown spot on the relatively new light fixture reflector.
This struck me as odd, but upon closer examination I found an arc point on the wire. Odd, because there is very little draw to the LED. You will see a tiny bit of tape I put over the wire.
After replacing everything I was looking at the LED and found an arc point in its insulation.
Now, it could be that one is an arc point and one is just a black spot but for sure, one arced to the reflector, which is painted white. I suppose I should look at the tiny red wires on all the LEDs... or blame it on vibration wear and forget the whole thing.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: LED House Light Oddity [message #270712 is a reply to message #270701] |
Thu, 29 January 2015 02:34  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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My initial reaction is fix the problem at hand and forget it. If it occurs again in some other light then you might do some additional investigation. I have replaced a lot of fuses in my life and I usually do not bother looking much for the problem until a second fuse blows in the same position. A nick in the insulation of a piece of wire shorting to ground is not all the unusual. I had one about 2 years ago in the wiring to a vent valve on my truck. I fixed the wire and forgot about it until you just reminded of it. I would not waste the CPU (brain) cycles worrying about it unless it fails again.
JMHO
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: LED House Light Oddity [message #270722 is a reply to message #270701] |
Thu, 29 January 2015 08:14 |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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Senior Member |
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George,
I take the opposite view than KenB, mainly because there is usually a reason the fuse has blown. If I drive an hour out and and back to fix an issue for a customer and find a blown fuse... I better find out why it blew otherwise when it blows again the customer will expect that to be a freebie service. There is a point though if you can't find the reason it blew, then you can't spend any more time on it.
Couple of things.
-12 volts does not "jump" (ok as the gap approaches zero it will but not across any insulation gap as in a crack in the insulation)
-Is that fixture made of plastic or metal?
-I'm suspecting metal, but even then the paint would insulate at 12V
I'm thinking there is a fault in the LEDs, either the socket adaptor (unsoldered wire strands shorting) or a faulty polarity protection diode broke down.
That black mark could have been on the fixture before, something baked on from the heat of the old incandescent. The wire could have picked up the mark.
Also check the LED mounting tape for component and wire leads poking through the tape. Those will eventually cut through the fixture paint and short.
I always hated intermittents and blown fuses. If I didn't find the reason for it, then I'm usually re-fixing it for free till I find the reason or I can convince the customer to replace it.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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| Re: LED House Light Oddity [message #270731 is a reply to message #270722] |
Thu, 29 January 2015 10:53 |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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Senior Member |
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RF_Burns wrote on Thu, 29 January 2015 06:14George,
I'm thinking there is a fault in the LEDs, either the socket adaptor (unsoldered wire strands shorting) or a faulty polarity protection diode broke down.
That black mark could have been on the fixture before, something baked on from the heat of the old incandescent. The wire could have picked up the mark.
Interesting about the diode. The LED no longer works so perhaps there was a fault with that unit. I am using the same socket and the new LED works fine. It could be that the insulation on those tiny wires is paper thin and I will have to be more careful when handling them.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: LED House Light Oddity [message #270803 is a reply to message #270722] |
Thu, 29 January 2015 22:20 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Bruce,
I do not disagree with your approach. The difference here is that he is working on his own coach. If it fails again he does not have to drive anywhere and put up with a dissatisfied customer. I have replaced I do not know how many fuses where the fuse was the actual failing item, or the cause of the failure could not be determined. In this case he saw what he believes was the failing component that caused the failure. I say replace or repair the failing component and replace the fuse. If it fails again then spend some additional time then to further analyze the situation.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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