Replacing Vetter Taillights with LEDs

Well, after 25 years of rattling around, the taillight sockets in my
Vetter trunk had worn out. It wasn't a safety issue. After all,
there were four lights, but, every once in a while (when I thought to
look), I'd find one out. The problem was never a bad bulb, and
reseating it always did the trick, but it's kind of uncool, riding
around with a taillight out. Thus, I decided to replace the original
sockets and bulbs with LEDs.

Yesterday, the weather was warm, and I was kicking myself for not
riding, but then the LEDs came in the mail, and it looked like this
week's cycling time was to be spent in the driveway. Then it snowed ~
3". The snow started before dark, too, and I would have been out in
it if I had not been hibernating.

However, today was a perfect spring day, so I was motivated to start
the job. Here's the before picture:

http://tinyurl.com/8yuco links to
http://www.excel.net/~crhode/Snaps/Geraldine%20~%20Old%20Vetter%20Lights%202006-01-21%2010.02.14.jpg

Here's the bill of materials:

> Qty Item Unit Extend
> 2 STL-78RB LED Stop/Turn/Tail Light $15.67 $31.34
> 1 *** Cork 3.49
> 8 M5x25 Round Cap Screws (black) .60 4.80
> 8 M5 Stop Nuts .30 2.40
> 8 M5 Fender Washers .15 1.20

The LEDs are made by Optronics:

http://www.optronicsinc.com/oemtruck3.htm

They are close kin to those sold in auto-parts stores, truck stops,
and farm-supply outlets. These are different, though. They are molded
into a shiny black bezel to be surface mounted.

The LEDs are available from:

http://www.lowcosttrailersupplies.com/Trailer_Parts/a-stl-78rb.html

When the brakes are off, the pair draws 0.084 A. They replace four
1157 dual-filament bulbs, which together draw 2.4 A. For comparison,
a pair of heated grips draws between 3.0 and 5.0 A.

The LED bezel is 7.5 x 3.25". Mount holes are centered on the long
edges and at the ends. The center of each hole is 0.25" in from the
edge. The front surface of the lens is 13/16" above the mounting
surface. The electrical wires are molded in. These LEDs are the bulk
variety, shipped with unterminated pigtails.

Chromed plastic trim rings are sold separately, and I bought them, but
I decided they were going to look too gaudy, so I wound up not using
them.

Problem #1: The Vetter mold has a recessed area for the left pair of
lights separate from the right pair. Interestingly, these areas are
just 7.5" wide. Unfortunately, the radius from the floor to the wall
of the area interferes.

Problem #2: The wires come out of the center of the back of the LED
normal to the mounting surface. Evidently, you are supposed to cut a
hole in the mounting surface, but I was concerned that the ABS plastic
trunk already had enough holes in it.

Here's the trunk with original sockets removed:

http://tinyurl.com/8jxzu links to
http://www.excel.net/~crhode/Snaps/Geraldine%20~%20No%20Vetter%20Lights%202006-01-21%2013.17.16.jpg

Yeah, I'm missing the Vetter badge.

Cutting a large hole for the wires would have made it difficult to
restore the original sockets (Who knows but that I may want to do that
someday?), so I decided to run the wires along the outside of the
trunk to the outer socket hole. Thus, it was necessary to relieve the
crimp in the wires at the back of each LED.

I solved both problems (and the lack of weather tightness due to
leaving so many holes) by cutting gaskets to go under the LEDs (which
do cover all the holes). (The LEDs themselves are supposed to be
weather tight.) I cut a slot for the wires through the middle of each
gasket, and I undercut the ends of each gasket to conform to the
radius of the plastic, so the LEDs wound up being mounted a tad off
the surface (the thickness of the gasket).

The LED bezels didn't have a broad surface touching the gaskets,
however, so I had to cut the gaskets a trifle large.

Now, I would have chopped up that old innertube I have somewhere
around here if I could have laid my hands on it, and the neighborhood
hardware store was out of *** rubber in the plumbing and roofing
departments, so I bought a handy-dandy roll of *** cork ~ the kind
that you glue to the bottoms of table lamps, and I cut the gaskets out
of that with scissors. Then I ran a black permanent marker around the
edges.

Here's a closeup the result:

http://tinyurl.com/8xgc7 links to
http://www.excel.net/~crhode/Snaps/Geraldine%20~%20New%20Vetter%20Lights%202006-01-21%2019.52.56.jpg

I should have polished off the filth left under the old sockets. You
can see the edges of it over the tops of the LED bezels because they
mount a little lower.

I test fitted the LEDs and marked the locations of the mount holes in
the plastic of the trunk with an awl. I used a straight edge to make
sure the marks were in line. Then I drilled pilot holes. It was a
good thing I did. That stuff was buttery soft, even at 34 F, Then, I
enlarged the holes with an ample bit. The outer mount holes
overlapped existing (unused) holes.

The 25 mm cap screws turned out to be way too long, so, after I had
tightened them, I whacked 1 cm off of each of them with a high-speed
cutting disk, moving from screw to screw, taking care not to overheat
one and melt the plastic of the trunk or the bezel. Actually, I used
a lot of disks, and, as often as I was breaking them, overheating
wasn't much of a problem. That was the most frustrating part of the
job.

If I had done it right, I'd have used 15 mm screws to begin with.
Then, the most frustrating part of the job would have been drilling
out the rivets holding the old sockets.

Vetter put two rivets in each socket ~ one at the top and one at the
bottom. The mount holes on either side were not used. The ground lug
was fastened under the bottom rivet on the outside between the plastic
of the trunk and the metal flange of the socket. After a quarter of a
century, this uneven pressure had caused the ABS to fracture around
the bottom rivet. While mounting the LEDs, I put fender washers on
the inside under the stop nuts to spread the load on the old plastic.

The torque needed to turn the stop nuts on the cap screws was more
than that needed to tighten down the LEDs on the gaskets. I backed
off the nuts a little to ease my fear about crushing the plastic
parts. If I had been able to find black nylon screws, I would have
used them.

Here's what the new taillights look like with the ignition on:

http://tinyurl.com/83f5c links to
http://www.excel.net/~crhode/Snaps/Geraldine%20~%20New%20Vetter%20Lights%202006-01-21%2014.19.32.jpg

What you don't see is how much more room I have inside the trunk now.

--
... Chuck Rhode, Sheboygan, WI, USA
... 1979 Honda Goldwing GL1000 (Geraldine)
... 1978 Honda Goldwing GL1000 (Fenris)
... 19°F. Wind S 9 mph. Clear.

.

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