Expert: Brad Sears - 8/3/2009

Question
Hello Vern,
I am in the process of fitting a tow bar to my 1949 Buick Super Sedanet, Model 56-S.
The car is on the standard stock 6 volt system.
The travel trailer that I intend to tow is a 1951 Silver Streak Clipper and is standard with 12 volt systems.
I also tow this trailer with my Toyota that has 12 volt system.
Can you advise the way to go with the hook up for lighting and ancillaries please?
Do you know of a 'magic box' that will handle the transition in voltage?
thanks in anticipation.
:o)

Answer
You have two problems here. The Toyota uses separate rear lights for the stop and directional while the Buick uses the same filament of the tail light for the stop and directional. here is a magic box that will accomplish the transfer from the Toyota to the trailer but the transition from 12 to 6 volt is a little different. There are two ways to approach the problem. First, take the lights apart on the trailer and fit a second set of bulbs inside the light assemblies, a separate wiring harness and trailer electrical plug for the Toyota. Second is to build a very simple relay system that will switch circuits for you.  When I was fitting my old car up for towing I built one of these for my motor home. There is nothing on the market to do what you want that I know of but a home built unit can be made easy enough. If you would like more information let me know.
Brad