I started back last week to see if I could find a way to get the taillights to work. After several tries I got things working. The problem was the fiber was too small and wasn't passing enough light. I went with a .03" fiber and it works fine.
The 1½ volt micro lights don't put out very much light so that's why the smaller fiber wouldn't work. The .03" fiber will carry enough light to light up the taillights.
The following pictures shows several vehicles on my roadway taken with subdued lighting. The road goes from the lower right up and through a tunnel then continues to the top turning to the right at Doug's Mountain Dinner.
You will have to excuse some of my unfinished scenery, my layout is a project under constant construction.
The picture below is a front view of the 1954 IH Metro Van and a early 50s VW Bug. Both have duel 1½ volt micro bulbs for headlights and one in the light to fiber connector.
The picture below is a rear view of the 1954 IH Metro Van and the 50s VW Bug. Both have .30" fiber optics cables connected to a 1½ volt micro bulb to light up the taillights. I heated the ends of the fibers with my soldering iron and formed the taillights with a small screwdriver. I then painted the fiber taillights with red Delta Transparent Glass Paint.
The Metro Van is appropriate on my layout, in the late 50s and early 60s when I worked for Industrial Communications in Alamogordo New Mexico I drove a 1954 Metro Van as a two-way radio service vehicle.
The picture above is taken at Doug's Mountain Dinner. The only vehicles with lights are the 1957 Chevy Convertible and the 1941 Ford Coupe. I will add lights to a few more of the vehicles parked here.
The following pictures are more finished vehicles.
The reflection of the headlights off the road adds a lot to the realism.
I will end up with a total of 49 vehicles with lighting on my layout. I'm currently working on three 1955 Lincolns, a 1954 VW Bus, a 1955 Porsche spider and a 1952 Greyhound Bus.
I use .030" fiber strands for taillights and the marker lights are .020" fiber. The fiber is lit up with 1½ volt micro bulbs also. I used my soldering pencil iron to melt the fiber and form the lights. I put a very small drop of Red & Amber Delta Transparent Glass Paint to color the fiber ends.