Voltage fluctuation 1997 Scamp 13

[nigeleccleston]

When I turn on an interior lamp (refitted with LED bulb), it takes a couple of seconds to light up, is dimmer than usual and brightness fluctuates. I test the voltage from the cigarette lighter power terminal and a similar thing happens - at first nothing registers and a couple of seconds later it shows 10.72 volts, 10.34, 9.98, etc. changing by the second.
The battery is fully charged and reads 12.74. Exterior 15 amp fuse is good. I do not have an onboard converter and the Scamp is not hooked up to my vehicle.
In researching, I've read posts here about hidden capacitors, pumps being on, etc. and I'm wondering where to start checking circuits. The battery does not run down so I don't think anything is actually drawing current continuously.
I recently returned from 4,000 miles of towing between Minnesota and Florida, could a ground be loose?
Thanks!

[gordon2]

Originally Posted by nigeleccleston

... at first nothing registers and a couple of seconds later it shows 10.72 volts, 10.34, 9.98, etc. changing by the second.
...

That sure sounds like a dead battery. It can show near full voltage for a short time after charging (called surface charge) but as soon as a load is put on the the small surface charge is dissipated and the battery cannot supply power. So first thing is to test the battery with a hydrometer (disconnected, after charging and resting for a few hours) or take it a Auto Parts store for a good test. If both those show it is OK then start checking amps flowing form the battery when you see the voltage drop and narrow it down. But my money is on a bad battery.

[AC0GV]

Originally Posted by nigeleccleston

I recently returned from 4,000 miles of towing between Minnesota and Florida, could a ground be loose?
Thanks!

It could be the ground (-) or hot (+) side, and the older Scamps had a rats nest of wire nuts in the wiring, I'd check them all. Check voltage every step of the way, Starting at the battery and working through every place you can get a meter on it. Please let us know what you find.

[varmint]

LEDs draw very little and probably aren't pulling down a battery. I'm guessing your problem is a poor connection. You say you have no converter. Your battery should supply some sort of distribution center. Check power at that point. Wire nuts, scotch locks, corroded grounds are just a few of the likely culprits. As to the 12.7v at the battery, did you check it with your light turned on? Turn on your fan or some other load that will draw some amperage. See if the battery drops to those low voltages you mentioned. Good luck and when you finally find the problem you will have a better understanding of your circuits.

[AC0GV]

Originally Posted by varmint

LEDs draw very little and probably aren't pulling down a battery.

And LEDs can run at a lower voltage and still look bright. Here is the new porch light style running on 9VDC.

[nigeleccleston]

Originally Posted by varmint

I'm guessing your problem is a poor connection.

I waited until the outside temp hit 40, went out and turned on the "porch" light. It worked as normal. I jiggled wires, starting at the battery, until it went out and found very quickly that the inline fuse assembly needs replacing.
It certainly wouldn't have hurt to get a better understanding of my circuits. I have replaced both rear exterior lights and wired in an AuTowbrake controller so I'm familiar with the wiring diagram but there are plenty of other things to go wrong.
Thanks everyone for your posts!

[bighead]

Originally Posted by nigeleccleston

When I turn on an interior lamp (refitted with LED bulb), it takes a couple of seconds to light up, is dimmer than usual and brightness fluctuates. I test the voltage from the cigarette lighter power terminal and a similar thing happens - at first nothing registers and a couple of seconds later it shows 10.72 volts, 10.34, 9.98, etc. changing by the second.
The battery is fully charged and reads 12.74. Exterior 15 amp fuse is good. I do not have an onboard converter and the Scamp is not hooked up to my vehicle.
In researching, I've read posts here about hidden capacitors, pumps being on, etc. and I'm wondering where to start checking circuits. The battery does not run down so I don't think anything is actually drawing current continuously.
I recently returned from 4,000 miles of towing between Minnesota and Florida, could a ground be loose?
Thanks!

check for a GOOD clean metal surface for a good ground.

[Darrell in Al]

Something that I had with replacement LED bulbs and then the LED burned out on a short time. I replaced most of the lights fixtures with LED lights fixtures. A lot of LED lightbulbs are for auto signal lights "turn, brakes signal's" not for running hours on end, I think ??? Mine is a 2010/11 model year Scamp.
"I didn't stay in a Holiday inn last night and I don't play a Electrician on TV"