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Topic: One single rear marker light staying illuminated with power off (Read 471 times) previous topic - next topic
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One single rear marker light staying illuminated with power off
Odd issue I’m encountering. My left rear lower signal marker light is staying dimly illuminated even with the power off and headlights turned off. No other lights are on.
When I pull the headlights switch out (on) the marker light works at the normal illumination and pushing the brake or turn signal works at normal brighter illumination as well. It just won’t turn completely off. So strange.
Joe B.
2008 26ft  grey/white Rear Bath
NE88 caravan club
Re: One single rear marker light staying illuminated with power off
Reply #1 –
Hi Joe;  What is odder, is that since that one light is connected to the 'running' lights' source (light brown wire) any leakage of 12v to that one marker light would be shared to all of the other marker lights.  I could believe that an LED array could very dimly show some light with a very small voltage, but it would have to be dark or very dim lighting to see it.  Yours appears to be pretty well lit.
    I suspect some salty condition in the nearby trailer socket connector allowing an always on (+12v) terminal to be leaking power back into the running light circuit. Check those connector pins, and the bundle of wires going to that socket for damage.  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: One single rear marker light staying illuminated with power off
Reply #2 –
My 1988 MB has a group of grounds wires there with a bus wire to Chassis.
Chassis ground is open. and likely the Fantastic fan is grounded there also.
Rodney
1988 Mid Bath
Re: One single rear marker light staying illuminated with power off
Reply #3 –
Thanks all. Honestly with hockey season starting up for my boys I haven’t had a chance to dig into this. Hmmm wonder where to start looking for loose grounds possibly. Will also check the receiver plug.
Joe B.
2008 26ft  grey/white Rear Bath
NE88 caravan club
Re: One single rear marker light staying illuminated with power off
Reply #4 –
Left Rear Marker light you have pictured. Remove the cover.
 My 1988 NB has 4 ground wires there. Then one buss wire to the Chassis/ rear coach attachment/ bumper.
Rodney
1988 Mid Bath
Re: One single rear marker light staying illuminated with power off
Reply #5 –
To add a layer of confusion the right rear marker light is staying barely illuminated on as well. Maybe that makes it less confusing actually. Either way still sorting it out. I need to pull the lens off.
Joe B.
2008 26ft  grey/white Rear Bath
NE88 caravan club
Re: One single rear marker light staying illuminated with power off
Reply #6 –
Hi Joe;  That actually makes more sense.  Use a digital voltmeter (high input impedance) to measure the voltage on some of the lights. If all of the lights have a voltage maybe 3-4v then the problem may be in the light switch on the dash.  Have you added any 'diodes' for towing lately?  Leakage paths can be hard to find.  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB
Re: One single rear marker light staying illuminated with power off
Reply #7 –
Looks like LED. They play havoc sometimes.   I'm going to search some more.
Ramon
2000 Mid-Bath
2012 Lance 830 Truck Camper/2006 Cummins Dodge Ram Megacab
1985 Multi Plan - Donated to the American Breast Cancer Foundation.
Re: One single rear marker light staying illuminated with power off
Reply #8 –
Quote from: RonB  - 
Hi Joe;  That actually makes more sense.  Use a digital voltmeter (high input impedance) to measure the voltage on some of the lights. If all of the lights have a voltage maybe 3-4v then the problem may be in the light switch on the dash.  Have you added any 'diodes' for towing lately?  Leakage paths can be hard to find.  RonB

Nope, we never tow. Just a bike rack on the hitch. They are indeed LEDs. The pull switch seems to operate fine in all positions and all other marker lights including overhead front/back turn off and on as normal. Again, apologizes as I haven't done my part to really dig into it but appreciate a few ideas of where to start. I assume it must be sometime fairly silly. It's just strange that it was initially only the left side lower marker for a few days and now I note the lower right marker light is very dull but illuminated.
Joe B.
2008 26ft  grey/white Rear Bath
NE88 caravan club
Re: One single rear marker light staying illuminated with power off
Reply #9 –
Now that you have noticed the other lower clearance light is illuminated, check all the upper clearance ights to see if they are also partially illuminated. Might be best to do this when it is dark.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: One single rear marker light staying illuminated with power off
Reply #10 –
Quote from: Larry W  - 
Now that you have noticed the other lower clearance light is illuminated, check all the upper clearance ights to see if they are also partially illuminated. Might be best to do this when it is dark.

Larry

This is the oddest part. None of them are even dimly lit. It is only the lower side rear marker lights. Today, although battery voltage seems to be the same, the two lights are BARELY illuminated less than they were a few days ago. So odd. If I pull the headlight knob they fully illuminate properly.

No issues with slow crank when turning on the engine so doesn’t feel like it’s draining the battery. I guess being LED helps.
Joe B.
2008 26ft  grey/white Rear Bath
NE88 caravan club
Re: One single rear marker light staying illuminated with power off
Reply #11 –
Did you put the LED lower markers in or when they on the rig?  And are the uppers LED? 
2000 Mid-Bath
2012 Lance 830 Truck Camper/2006 Cummins Dodge Ram Megacab
1985 Multi Plan - Donated to the American Breast Cancer Foundation.
Re: One single rear marker light staying illuminated with power off
Reply #12 –
Quote from: mrfixit454  - 
Did you put the LED lower markers in or when they on the rig?  And are the uppers LED?

LEDs being diodes and passing power in one direction only may have something to do with this, it is puzzling
Tail and running lights with ground and back-feeding issues can use many hours searching for the cause and can be the most irritating problems a mechanic can run into.
BTDT too many times.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze