Better Beaters - Building Cars and Daily Drivers

 Adding a CHMSL ; a Center High mounted Stop Lamp to my Plymouth.  

The lamps have the proper vintage look, they're probably older than the car.

As I have previously written, I am not too enthused by the single brake lamp mounted on the trunk lid of my Plymouth.

For one thing it's not very bright, and second, there's no back up if the bulb should burn out. Besides, I don't think that modern drivers are looking at license plate mount height, they're used to seeing the CHMSL in the rear window.

Back when they were introduced there were many aftermarket units available from JC Whitney and other places like Pep Boys. I haven't seen one offered for sale in many years. I might be able to find one at a swap meet, though I don't think that the modern design would match my car.

My plan was to go to an antique car swap meet and see if I could find a couple of vintage light assemblies that would work in my situation.

I went to a swap meet held at the Ford V8 parts store in Campbell, which was not far from my house. This store sells OEM and reproduction parts for Fords from the flat head era. They usually hold a swap meet once a year. 

I found a couple of old trailer lights. They are 2 1/2 inches in size and have a very neat looking glass lens, with a single mounting stud. 

I considered mounting them to the rear bumper, but my car has a full coverage gravel shield in place. I was not going to drill holes in that. I also considered attaching them on a bracket mounted to the license plate. But I thought that would look too tacked on. Then I considered placing them where they would be visible through the rear window, mounted to the package tray.

First I dis-assembled the lights and checked the sockets. They were okay to use. I sanded and painted the housings matte black, blocking off the license plate lens. Then I added some aluminum foil as a reflector.  I figured that I could build a pedestal mount out of aluminum angle and flat stock from the local OSH hardware store. I made cardboard templates to determine the lamp spacing in the cross bar and to figure out the height of the pedestal. Again, I didn't want to drill holes in the car. I found a piece of 2x6 lumber that I had left over from an earlier project. I found that it fit into the available space and serve a base for the assembly quite well. I would attach the upright to that. I found that I could order six volt bulbs from my local NAPA store, these aren't generally available at the local O'Reillys. I wired up a new harness to the original sockets with plenty of extra length. I'd learned that it is always best to allow a lot of extra length when stringing wire circuits.

I wish that I had photographed the entire build process, but I've been pretty busy lately and didn't want to take the time. I used 1 1/2 inch flat and angle stock. I bolted two pieces of angle back to back forming a "T" cross section. That would be plenty strong to hold the two lamps without flexing. 

Once I had the entire unit assembled I hooked it up directly to the battery to test it. It was quite bright when it lit up. 

The design is pretty straight forward. 

I fastened the metal pieces together with small round head screws and nuts, trimming off the excess length of the screws. To give it a bit of a finished look, I rounded off all the sharp corners and drilled some lightening holes, a real '40's aviation look! 

The CHMSL worked pretty well though I do have some concerns about the wiring. The wire feeding the license plate lamp is 14 gauge, while the wire to the brake light is only 16 gauge. Maybe a little too light to handle the three lamps. I'll have to keep an eye on that. 

However it is reassuring to know that I've got a trio of lights warning traffic behind me when I hit the brakes.