1948-52 Dim Stoplights

[Bob Schuman]

The stoplights and rear turn signals on my 49 and 51 Cadillacs are almost invisible to following drivers on sunny days. The cars are stock 6 volts, with halogen replacement bulbs in the rear lights, and I have checked the bulb aiming as Art Gardner described some time ago, but still I feel unsafe with people telling me my stoplights do not work.

Does anyone have a good fix to significantly improve the brightness and visibility of these lights? I mentioned 48-52 in the title, because I expect that the 12 volts system used in 1953 and later corrected this deficiency.

Bob Schuman

[bcroe]

With new halogen bulbs, they should be fine.  If the same wattage as 12V, there
would be no difference in brightness. 

I suspect either the bulbs are not getting full voltage, or the red lens has
gotten more opaque with age (this happened to me).  Check it out. 
Bruce Roe

[Caddy Wizard]

Bob,

Here are some of my tricks for better brake lights:

Add an auxiliary ground wire to each housing.

Clean the inside of the lenses, especially the Fresnel lens portion.

Polish the outside of the lenses with plastic lens polish available from parts stores.

Polish the chrome plating in the lamp housing and make sure everything in there is spiffy clean.

Make sure that the basic grounding system of the body and chassis is PERFECT.  Clean the grounds at the firewall (which is how the body gets grounded), at the back of the cylinder heads, at the frame, and at the starter. 


You should be able to get decent illumination.  Personally, I also run a 6v PowerGen alternator, which keeps the voltage up when you take your foot off the gas and step on the brake.  Looks like a generator, but provides full voltage and good amperage at idle (when you need the brake lights to work).  I know that many will eschew such a change, but I have been very happy with these over the years.


One more thing to consider.  Sometimes the brake light switch is coming on at too high of a pressure and will not initially close the circuit unless you really mash the brakes.  So maybe a new switch is in order.  Ron Francis Wiring sells an improved version of the switch, one that comes on at a lower pressure.

[Jeff Rosansky CLC #28373]

I would suggest cleaning the bulb sockets. Spray them with contact cleaner and stick a piece of scotch Brite on the end of a screwdriver and twist. You will clean both the positive and negative sides of the socket at the same time this way. You will probably get a lot of crud off of them. I did that on the plane one year because the fuse would get warm (not hot). Did that and it runs much cooler now.
Jeff