LED bulb replacement

[CADjockey]

Good Evening!
Has anyone experienced a situation where by replacing an incandescent bulb with an LED one, several smaller incandescent bulbs no longer lit up?
Ultimately, I had planned on replacing all of the exterior camper incandescent bulbs with LED bulbs. I was checking things incrementally just to make sure everything was working normally and noticed that I lost the small bulbs
I believe I have narrowed things down to one set of bulbs. The tail/brake lights use 3157 bulbs. When I have incandescent bulbs in, all rear lights (C194 bulbs) work (but are a bit dimmer than I would like).
When I replace the driver's side tail light bulb (3157), the DS rear side marker light (C194) goes out.
If the DS tail light is LED, and PS tail light is incandescent, only the DS rear side marker light is out.
When I replace the passenger side tail light bub, the PS rear side marker and all small rear lights across the back of the trailer (also C194) go out.

Will these lights come back on if/when I replace the small lights?
I would have thought that the LED bulbs would have a lower amperage draw and so the other lights would be unaffected. Let me verify that though.

 

[BillK]

I wonder if they are wired in series ? Before you changed to the LED if you took one bulb out would the others keep working ?

 

[CADjockey]

ahhhh....
In doing more research on both types of bulbs, I am learning things that I was unaware of.
Both bulbs are rated for ≈12V.
BUT...
The amperage draw is actually a touch higher on the LED one. 2.1 amps for the incandescent compared to 2.3amps for the LED one. The lumens are where the LED really 'shines' (pun intended) though. 2500 lumens for the LED compared to 402 for the incandescent.

So now I feel that I have a little more understanding. would this small increase in amperage draw cause the downstream incandescent lights to go out? By replacing all bulbs with LEDs, am I still going to be fighting getting the downstream lights to work?

 

[Firebrick43]

Good Evening!
Has anyone experienced a situation where by replacing an incandescent bulb with an LED one, several smaller incandescent bulbs no longer lit up?
Ultimately, I had planned on replacing all of the exterior camper incandescent bulbs with LED bulbs. I was checking things incrementally just to make sure everything was working normally and noticed that I lost the small bulbs
I believe I have narrowed things down to one set of bulbs. The tail/brake lights use 3157 bulbs. When I have incandescent bulbs in, all rear lights (C194 bulbs) work (but are a bit dimmer than I would like).
When I replace the driver's side tail light bulb (3157), the DS rear side marker light (C194) goes out.
If the DS tail light is LED, and PS tail light is incandescent, only the DS rear side marker light is out.
When I replace the passenger side tail light bub, the PS rear side marker and all small rear lights across the back of the trailer (also C194) go out.

Will these lights come back on if/when I replace the small lights?
I would have thought that the LED bulbs would have a lower amperage draw and so the other lights would be unaffected. Let me verify that though.

The only place that LED lights should affect is mechanical flasher units on turn signals. More I think about it you may have a poor shared ground at the tail light and messing with the socket causes the ground and therefore the light to fail. Removing the bulb or changing the bulb should not affect anything else as they should be wired in parallel. The higher amp draw would only affect things if it popped the fuse or tripped the circuit breaker on that circuit.

 

[The Cobbler]

I can't see 0.2 amps causing that , but also have no thoughts

 

[CADjockey]

I wonder if they are wired in series ? Before you changed to the LED if you took one bulb out would the others keep working ?

hmmm.... I do not know. Let me go check that real quick.

 

[CADjockey]

I think we are good there.
I put the incandescent bulbs back in the tail lights, turned the lights on, then yanked one of the tail light bulbs. The other bulbs remained on.

 

[Gmonkee]

Is the vehicle the camper is connected to one of those that uses the on-board computer to monitor the lights?

Those can go haywire if amperages change and readings go out of range.

 

[CADjockey]

The camper is a 2001 pop-up. Seems like the entire camper tries to give a basic, or primitive feeling.
From what I have seen in my inspection, there is not anything computerized in the camper.

The vehicle it is currently on is a 2004 Chevy Suburban. I know many things on it are computerized, but I do not know if the lights on anything towed are being monitored at all. And honestly, I am not sure how to check for that. If there is a way, can you share it with me?
It does have a towing package, with the e-brakes and all. But the camper does not have e-brakes. I had to get a 7-pin round to 4-pin flat adapter just to plug the thing in.

 

[BillK]

I guess I missed the part about exactly what you were working on. I thought you were working on exterior lights on a big rv, not brake and tail lights.

If you want to be certain that it isnt a problem with the tow vehicle just get a 12 volt battery and hook the trailer up to it and see what happens.

I do know that even my 1999 Tahoe has circuit boards in the tail lights that will do strange stuff so dont rule it out.

 

[Gmonkee]

Basic camper,, fairly basic truck as electronics goes.
You probably have a bad ground within the system or corroded connection points.

Inspect everything well and prepare to replace small bits here and there.

 

[Wrench97]

Sometimes you'll find the ground for side marker lights(the little ones) wired through the turn signal filament on the larger bulb this will allow it to blink off went the T/S lights and stay on pulling the ground through the bulb when the T/Sig is not on.
LED's won't work the same way, so figure out what you are missing either power or ground and rewire it.

 

[CADjockey]

Well phooey! I am now really confused.
I got my small bulb LED (C194) replacements delivered today, so I stuck those in and tried things out. I am using 7 small LEDs - 5 across the back and the 2 rear side marker lights.

If I have ONE (either) of the TLs as an incandescent (the other can be an LED) then they all work. If I replace both TLs to LED then all of the marker lights fail to light.

My only guess at this point, is the amperage draw. But I am NOT anything close to being electronic adept, so my guess can be completely wrong.