Pulsing marker lights and unknown switch

philbtv · 02-17-2022, 09:28 PM

Just bringing the 5th wheel home to install the new slide wiper seals today. I noticed, while doing my walk around, that the marker lights on the rear of the trailer pulsed and dimmed slightly when the blinkers were on. The trailer was in the shade of the covered parking but it was noticeable. Any ideas on the cause of this and any possible solutions?

The second thing is there is a switch on the interior control panel marked "FLOOD". When I turn the switch on I can't find a light to go with it> It isn't the "Pendant" LED light strip under the awning, it isn't the "Porch" light under the steps and it isn't any of the front cap lights. Is this just a switch in the panel that is used for other models? Thanks in advance for the flood of knowledge about to come my way!

**flybouy** · 02-18-2022, 05:13 AM

Is this a new to camper or a new issue (at least with the lights dimming) that didn’t appear previously.? My first inclination on the dimming running lighrs would be to check the 7 way plug for corrosion or loose fit. Then check and confirm a good ground conncention from truck to trailer. If you have a freind with a truck that can plug into your trailer that would be the fastest way to isolate if the issue is the truck or the trailer.

I don't have your model trailer so the flood light is a guess. Do you have a large round light on the goor side mounted high at the front? Typically they are called scare lights but maybe a name change? Just guessing.

philbtv · 02-18-2022, 08:04 AM

Thanks flybouy! I can't honestly say if the dimming is new or not. It just happens to be the first time I have noticed it. It's just our second year with this RV. I'll check the plug and ground. We bought the unit used and the 7 pin connector is rough around the edges, as if it were dragged across the ground a bit (don't ask me how the original owner did that one.) We also live in a dusty part of central Washington and there was dust inside the receptical on the pick up. We had the pick up wired for the 5th wheel by the local RV dealer when they installed the hitch.

No big lights on the door side, street side, or any other side...the search continues. Thanks.

**flybouy** · 02-18-2022, 08:52 AM

Quote:

Originally Posted by philbtv

Thanks flybouy! I can't honestly say if the dimming is new or not. It just happens to be the first time I have noticed it. It's just our second year with this RV. I'll check the plug and ground. We bought the unit used and the 7 pin connector is rough around the edges, as if it were dragged across the ground a bit (don't ask me how the original owner did that one.) We also live in a dusty part of central Washington and there was dust inside the receptical on the pick up. We had the pick up wired for the 5th wheel by the local RV dealer when they installed the hitch.

No big lights on the door side, street side, or any other side...the search continues. Thanks.

Try some electric contact cleaner I use CRC brand. Spray it out to clean it (both plug and receptical) then take a close look at the contacts. You can buy a small round brass brush made specificaly for that task. I do that at the beggining of every season then put some dielectric grease in the plug. It's works well for me for many years.

philbtv · 02-18-2022, 08:55 AM

Will do, thanks!

**flybouy** · 02-18-2022, 11:47 AM

For your mystery switch, pull it out of the wall and see if you have 12v dc going to and out of the switch. If you do, then I'd turn on all the light switches and note what's on, inside and out. Then turn just that switch off and look again. If a light is not on you found it. If not then turn the switch on and start looking for a fixture not on. It could be a light fixture under the trailer say to illuminate the dump valve or somewhere else not obvious to the casual search. Could be a night light inside the trailer.

Hopefully someone with the same unit will stop by and "illuminate" us on what that switch is for. Good luck on your search.

**JRTJH** · 02-18-2022, 12:06 PM

Keep in mind that if the bulb in the "switched fixture" is blown or damaged, then no amount of "flipping the switch" will cause the blub to flicker, so if nothing happens, it may be a blown bulb or a defective fixture and a perfectly functional circuit.....

Ain't Easter egg hunts wunnerful ?????

LHaven · 02-18-2022, 04:18 PM

Quote:

Originally Posted by flybouy

I'd turn on all the light switches and note what's on, inside and out. Then turn just that switch off and look again. If a light is not on you found it. If not then turn the switch on and start looking for a fixture not on.

Just saying, it would be a heck of a lot easier to do this test at night with all of the other switches off!!

**JRTJH** · 02-18-2022, 07:18 PM

Quote:

Originally Posted by LHaven

Just saying, it would be a heck of a lot easier to do this test at night with all of the other switches off!!

Assuming the bulb in the fixture is operational and, if there's a switch on the fixture, it's turned on.... If the bulb is blown, day or night won't make it easier to find and if there's a switch on the fixture that's turned off, same as a blown bulb, flipping the switch won't get you anywhere other than closer to the "mean time to switch failure"....

Old Mustanger · 02-18-2022, 08:16 PM

One other thing you might want to check as far as the pulsing lights are concerned is your truck's alternator output (I assume the truck was idling when you noticed this).

philbtv · 02-19-2022, 09:14 AM

Good point as it was during idle. Thanks.

philbtv · 02-19-2022, 09:19 AM

Thanks JRTJH and LHaven! I will resume my search tonight. As far as easter egg hunts go it is almost March, right?

Ddaddyo · 03-03-2022, 08:27 AM

When the lights Pulse with the Blinkers you have an Inadequate ground.

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