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.