Question on installing dimmer switch

[larry2c]

I bought this dimmer switch to use on our awning strip light - the thing is way to bright. This switch needs both the + and - input and output to work. When I pulled our main switch panel out there is only one wire running to the switch (and one out). I put my volt/ohm meter on the lead at both sides of the switch and there is no voltage shown.

The awning light is working so I assume the switch is making/breaking the ground side for the awning light. Does that make sense? I always thought that you broke the positive side on a DC circuit.

There is no real/easy access to the wires from the strip - they come down the awning channel a ways and then go into the wall in a spot with no access from the interior.

I'm not a whiz at electronics so I'm hoping that maybe someone here can give me some pointers on how to incorporate this switch into our awning light.

Thanks!

[larry2c]

I see that a lot of folks looked at this post but nobody had any suggestions. I decided that I'd make it work "my way" so here's what I did. The wires out of the awning light strip enter the trailer at the bottom of the aluminum channel from the front awning support.

I measured the location of the entry and then went inside the trailer and measured over where I believed the exterior entry point was. This location is about 6" forward of the wall to the refrigerator cabinet and about 12" above floor level. I took a 1" hole saw and carefully drilled through the interior paneling. My position was perfect and through the hole I could see the wires entering the gap between the outer wall and interior paneling. I figured out which pair of wires were the right ones (verified with a multimeter) and removed the crimp connectors that were right there. I wired the new switch in and mounted it to the wall.

It works perfectly - from making the light strip off, to pinpoints of light, to the brighter than the sun factory on condition! The control isn't as convenient as it would have been over the actual awning light switch but honestly, once I set it for a reasonable light level I doubt I'll change it much. The location is out of normal sight because the privacy curtain for the bed area hangs over it.

So not the most elegant solution but it is workable for us and now we can have our awning lights on without being blinded - or blinding the neighbors.

[NJKris]

larry, if you have no hots going to the switch and the circuit is energized, I would say you are correct that the switch is completing the circuit on the ground leg. Makes sense to me!

[Happy Camper 2715]

If I understood you correctly, the way you checked for voltage will not work. What you are doing would work for measuring current ,but not voltage.With the switch in the On or Closed position You need to go from one side of the switch with one lead and put the other lead from the meter on a known ground.If it read"s a negative voltage then swap lead's around.

[cavie]

Originally Posted by larry2c

I bought this dimmer switch to use on our awning strip light - the thing is way to bright. This switch needs both the + and - input and output to work. When I pulled our main switch panel out there is only one wire running to the switch (and one out). I put my volt/ohm meter on the lead at both sides of the switch and there is no voltage shown.

The awning light is working so I assume the switch is making/breaking the ground side for the awning light. Does that make sense? I always thought that you broke the positive side on a DC circuit.

There is no real/easy access to the wires from the strip - they come down the awning channel a ways and then go into the wall in a spot with no access from the interior.

I'm not a whiz at electronics so I'm hoping that maybe someone here can give me some pointers on how to incorporate this switch into our awning light.

Thanks!

This is why I try to help DIY's. You have it ALL WRONG. You always break the HOT wire in any electric circuit no matter if it's AC or DC. The wire you broke was 12 v DC. You didn't get any voltage because of it being only the hot wire. If your dimmer says it needs both Positive and negative to work it probably won't work for long.

[cavie]

Originally Posted by larry2c

I see that a lot of folks looked at this post but nobody had any suggestions. I decided that I'd make it work "my way" so here's what I did. The wires out of the awning light strip enter the trailer at the bottom of the aluminum channel from the front awning support.

I measured the location of the entry and then went inside the trailer and measured over where I believed the exterior entry point was. This location is about 6" forward of the wall to the refrigerator cabinet and about 12" above floor level. I took a 1" hole saw and carefully drilled through the interior paneling. My position was perfect and through the hole I could see the wires entering the gap between the outer wall and interior paneling. I figured out which pair of wires were the right ones (verified with a multimeter) and removed the crimp connectors that were right there. I wired the new switch in and mounted it to the wall.

It works perfectly - from making the light strip off, to pinpoints of light, to the brighter than the sun factory on condition! The control isn't as convenient as it would have been over the actual awning light switch but honestly, once I set it for a reasonable light level I doubt I'll change it much. The location is out of normal sight because the privacy curtain for the bed area hangs over it.

So not the most elegant solution but it is workable for us and now we can have our awning lights on without being blinded - or blinding the neighbors.

LED's are polarized. As your direction stated you need Positive and negative in. and positive and neg out. It won't work for long. It may posably flicker when dimmed. How many wires or attachment points are on the dimmer?

[Bama Rambler]

Originally Posted by cavie

... You always break the HOT wire in any electric circuit no matter if it's AC or DC.

That's not true. You ever looked at automotive schematics? They break the negative side of circuits all the time. And it's standard practice for them. Even some industrial controls break the negative side of certain circuits.

[rockfordroo]

Originally Posted by Bama Rambler

That's not true. You ever looked at automotive schematics? They break the negative side of circuits all the time. And it's standard practice for them. Even some industrial controls break the negative side of certain circuits.

X2. GM was notorious for this back in the 70's. But I think they've gotten away from it more these days.

That said, I'm not aware of any RV circuits switching the negative, except perhaps some battery disconnects (a whole 'nother debate!).

[Jay2504]

I have the exact same dimmer, but haven’t installed it yet. There are 4 connection, power and ground in,and power and ground to the LED strip. I don’t think that it matters which side of the incoming power/ground that is switched at the switch panel. In my case, (Rockwood 22504s) I believe the power side is switched. A question for the OP, when dimmed about half is there any flickering? Jay

[cavie]

Originally Posted by Bama Rambler

That's not true. You ever looked at automotive schematics? They break the negative side of circuits all the time. And it's standard practice for them. Even some industrial controls break the negative side of certain circuits.

I attempt to keep my answers short and understandable for the newbies. I refer to RV's and residential electricity in my answers on this forum. I do not attempt to show my intelligence with industrial electronics our automotive electronics when helping out with simple electric circuitry. Electric 101 is all that is required here.

[larry2c]

So just to be clear, I did check the actual switch on the FR main control panel from each side of the switch to ground (after I checked them to each other). When I found neither wire was "hot" I assumed that the switch was cutting the ground wire for the patio/awning lights.

When I drilled the hole in the wall I was accessing the actual pair of wires that run up to the LED light strip on the awning. I had to do a bit of multi-meter testing to determine that A) I had the right pair of wires because there were several pairs, and B) that I knew which was the hot side so I could get the switch wired up properly.

After I was all done, the dimmer works perfectly. To answer Jay's question - I have not noticed any flickering but now that you've mentioned it, I'll double check next time I'm outside after dark - and can remember