Trailer Lights

I've had good luck with the totally encapsulated lights, but you can't easily find a replacement on the road.

Then I tried the LED jobs...they're expensive and I found them unpredictable -- maybe because I used them quite a while back, the newer ones might be better?.

My current trailer came with tractor lights w/ bulbs, good for one dunking unless unplugged. When I bought trailer lights to replace the tractor jobs, I got the kind that use a regular 1157 bulb and rely on a pocket of air to keep the bulb dry. If you ever need a replacement bulb, you can find this one anywhere.

But with steep ramps and wakes at the ramp and jockeying the trailer while loading and unloading, sometimes  water gets into the air pocket and pops the bulb. I refuse to unplug the trailer, not because it will disconnect my all electric brakes, but because I'm lazy.

I decided to try some 1157 LED bulbs. They're a little over $2 each if you get them from eBay/China (as opposed to the $12 replacement capsules).

Knowing that these LED bulbs might get wet, I looked into a way to reduce the possibility of water messing with their innards. A test showed a rather simple solution...

I wrapped some Saran Wrap around the bulb and secured the wrap to the base with a twist tie (like you find on a bread wrapper). This was only a temporary seal for the first part of the experiment.

I then plugged the Saran Wrapped LED bulb into the socket, put the cover on the fixture and gave both pins 12 volts so the bulb would be at it's highest output.

I left the wrapped bulb on overnight to see how the plastic wrap would fare in the heat generated by the LED's. The Saran Wrap was completely in tact the next morning; the bulb was just barely warm to the touch. I'll redo the Saran Wrap before installation on the trailer, using silicone for a watertite seal of the wrap.

And today, my 18 month old grandson found fascination with the removed 1157 bulb while we were playing in the shop. He headed out the door with it. Fearing a fall, I took the glass bulb from him and gave him the 1157 LED variety. When his mom saw he had something 'metal' she told him to drop it.

I heard, "What has he got?" from the girls as my dog Merlin threw something in the air, caught it and buried it. As I came out to see what was going on, Merlin dug it up and reburied it in another spot. I chased him around the yard until I could see that he was playing with the LED bulb that Patrick dropped. It took a several minutes to get it from Merlin. He likes to run off, then drop it so I can see it. When I go to get it he waits until I'm close, then snatches it up and runs off to do it again. There's no catching him until he gives in, but I had to keep playing because I didn't want to lose track of the bulb. I finally did get hold of it and before wasting any time cleaning it I gave it some juice to see if it would work - and it did, shining through the dirt and dog spit.

So this is a testament to the LED 1157's, at least so far. I'll update this entry after the wrapped LED cluster has some miles and dunks.

UPDATE 12/20
The LED bulbs tested Ok on the bench - exhibiting a stronger illumination on one hot pin than the other, so I had no hesitation installing them in the manner above and did. I tested them again on the trailer with the red lenses off in case they didn't perform as expected. They seemed OK.

However, in preparation for an outing, I checked them again at night with the red lenses installed. The running lights were 'dim' and the brake lights were 'not quite as dim'. In addition, when the brake lights were on, they energized the running light circuit, so a turn signal would pulse the tail lights as well as the clearance lights. At first I thought this was a wiring/ground problem but when I got the LED's back on the bench it was apparent that the running and brake circuits had a common attachment - in other words, the running lights light up all the LED's in of the bulb in a 'dim' mode and the brake light lights up all the LED's in a brighter mode. It's like the brake light circuit bypasses a resistor that makes the running lights a little dimmer, but this means that the brake lights feed back to the other running lights on the entire trailer. This was confirmed by a voltage test of the bulb's pins - put 12 volts to the brake side of the bulb and you get 10+ volts out of the running light side...so we're back to the standard 1157's.