| Odd electrical stuff!! [message #371093] |
Sat, 25 February 2023 07:51  |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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Last night the wife and I are watching TV in our coach. Suddenly all lights in the coach go out, and the TV amplifier goes out. Microwave, TV's, and fridge still operating. So,something in the 12v system popped. Finally find that the fuse for lights has popped. All lights are LED's. So, I replace the 10amp fuse and it pops immediately. So,I go to a 15 amp and it pops. I then turned off all lights and inserted a 20amp amp fuse. One at a time I start turning on lights. When I get to the light over my reading area, the light does not come on, but instead the light over the pantry comes on. My reading area light switch is controlling the light over the pantry. HUH? Turned off the reading area switch and checked the switch at the pantry light and it works fine turning on and off the pantry light. So,I put the 10amp fuse back in and put a piece of duct tape over my reading light switch so I don't try to use it. WTF? Today I'm gonna replace the reading light LED, Something odd happening there.
Larry 
78 Royale w/500 Caddy
Menomonie, WI.
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| Re: Odd electrical stuff!! [message #371094 is a reply to message #371093] |
Sat, 25 February 2023 08:43  |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Guessing from afar, an LED failed in shorted mode, took out the fuse and at that time, or when you put in a oversized fuse, also opened a ground that was already oxidized and making a barely good connection. Up till then, the LED draw was not enough to make the questionable ground noticeable.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Odd electrical stuff!! [message #371100 is a reply to message #371093] |
Mon, 27 February 2023 14:24 |
Russell K.
Messages: 178
Registered: October 2016
Location: Dunedin, Florida
Karma: 4
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Hi Larry,
If you're talking about the reading lights in the back of the coach, under the cabinets; those lights in our '78 have the polarity reversed. We still have incandescent bulbs in them for now, and LEDs elsewhere. Your Royale may be wired differently. I think John L. is probably right that the LED shorted out when it died, burning out the fuse. The short may have also temporarily "re-routed" the grounding path causing the funky switch problem. Did switch functionality return after replacing the bulb? Electrical challenges have been the theme for our coach as well this year. Lots to talk about at the rally this weekend. See you then.
Russell
1978 Eleganza II, Dunedin, Florida
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| Re: Odd electrical stuff!! [message #371102 is a reply to message #371093] |
Tue, 28 February 2023 02:47 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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Larry wrote on Sat, 25 February 2023 07:51Last night the wife and I are watching TV in our coach. Suddenly all lights in the coach go out, and the TV amplifier goes out. Microwave, TV's, and fridge still operating. So,something in the 12v system popped. Finally find that the fuse for lights has popped. All lights are LED's. So, I replace the 10amp fuse and it pops immediately. So,I go to a 15 amp and it pops. I then turned off all lights and inserted a 20amp amp fuse. One at a time I start turning on lights. When I get to the light over my reading area, the light does not come on, but instead the light over the pantry comes on. My reading area light switch is controlling the light over the pantry. HUH? Turned off the reading area switch and checked the switch at the pantry light and it works fine turning on and off the pantry light. So,I put the 10amp fuse back in and put a piece of duct tape over my reading light switch so I don't try to use it. WTF? Today I'm gonna replace the reading light LED, Something odd happening there.
Welcome to the world of shooting electrical problems 1960's style. In a previous life I was a Signal Corps Sargent in a lead covered cable and telephone exchange outfit. So besides normal construction work we also did all of the cable ad telephone and telephone exchange repair in the country.
In the signal corp we would sometimes chase noisy and intermittent phone pairs using your technique which was raise the current until it fixed itself or burned itself open. When we could not find the problem normally, we would isolate the pair, stick a 400 or 500 watt light bulb on one end of the bad pair, and put around 120 volts (usually DC) on the other end. The current would either burn the noisy spot and short it together or burn it open. If it burned together it was fixed, unless it went to ground. If it was open we could now find it using normal means.
In civilian life, I was an electrician in a very large Steel Mill. In the steel mill the procedure was similar to your's. One night I got a call that one cranes had all of it's bridge lights out. I replaced the standard 250 volt 30 amp fuse for the circuit and it blew immediately. (The cranes ran on 250 volts DC.) So I went to 60 amp. Same thing. At 90 amps it did not blow and the lights were flickering. So I went looking for the short with power on and found a red / orage glow in the side of a 4" conduit about 40 feet down the bridge. It burned a hole in the side before I got back down the bridge to the cab to shut it off.
Production was everything and they needed the crane. So got two 500 spools of 12 ga. wire and ran a temp circuit across the bridge. I then wired each lights to the temp wires wires that I had just run. It took a couple of hours and the adjacent cranes kept pushing my crane side to side go to get it out of the way as needed for production. Also that bay had some annealing furnaces and every tine they pushed me across the top of them it was hot, hot, hot up there.
So using your technique I think you will find an open ground and what he other guys are saying probably a shorted bulb or socket.
I hope you liked by stories.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Odd electrical stuff!! [message #371103 is a reply to message #371102] |
Tue, 28 February 2023 07:01 |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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Senior Member |
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Ken Burton wrote on Tue, 28 February 2023 02:47
So using your technique I think you will find an open ground and what he other guys are saying probably a shorted bulb or socket.
I hope you liked by stories.
Always find your stories informative and sometimes amusing. Don't stop telling them!!
The 4 fixtures that I have in the cabin area do not have bulbs in them. Something goes haywire and the fixture has to be replaced. Two fixtures are above the dinette and are our reading area. The other two are above the kitchen area. One above the 2 burner stove and the other above the sink. Only rarely use the one above the stove so I took it down, and put in it in place of the burned out reading light above the dinette. Al is working as it should now, just no light above the stove. Have not had the time to test the faulty light fixture yet, but will try to get to it today. TTYL
Larry
78 Royale w/500 Caddy
Menomonie, WI.
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