today I was messing around with the marker lights on my 55 F350 flatbed. I was certain that there were 12 volt bulbs in as one was bright and all the rest were dim. Yesterday I bought the 6 volt bulbs and put them in today. They are all brighter now. Two bulbs were rusted fast so I had to break the bulb and use a needle nose to get them out.

Tonight after I got cleaned up and ate I decided to look into my parking lights. One was bright and one was dim. The one that was bright was very bright and the dim one looked like a parking light should look. Much to my surprise both sockets were double filament sockets with double filament bulbs. So one bulb was on the normal parking light filament while the other was on the bright "turn signal/brake light filament.

I switched the bulbs. The bulb that was bright on the left was now bright on the right. Anyhow I found another double filament 6 volt bulb and I put that in. So now both parking lights are the same brightness.

My puzzlement is this: My truck has the turnsignals mounted on the fenders. It does have the self cancelling dealer or factory installed turn signal switch. Even the little green arrows light up in the instrument panel. But why would the parking lights have the double filament sockets if the turn signals lights are mounted on the fenders? Dealer mistake? The buyers request?



What do you think?

I am sort of thinking of wiring up the parking lights so both the lights on the fenders and the parking lights will blink as turnsignals.

 

The truck has double filament park/turn signal bulbs, so the truck either came with factory installed turn signals...or were dealer installed after the fact.

The fender mounted lamps were probably installed by the dealer or by the owner...after the fact...as they can be seen from the front and the back.

B7C-13368-A (replaced FAA-13368-A) .. Lamp Assy. - Front Turn Indicator - Outboard Type

1957/63 catalog says: When using on units (trucks) with 6 volt system, change bulb.