I want to convert the parking lights, front bed clearance lights and possibly the out side cab lights to use also as turn signals on my '49 F4. I have seen the contact kit to convert to dual filament bulbs at Ron Francis Wiring and I'm sure others have them also. The photos show that the contact insulator is round, so what would keep the contacts from turning when you install the bulb so they will line up properly with the contacts on the bulb? Or is it best to replace the socket with the proper type?
Thanks, Mark

 

I think you need an indexed socket, with the two pins at different depths. The round insulator with contacts usually has "ears" that ride in grooves in the socket to keep them from rotating.

 

I used press-in indexed sockets in my Model A taillights. These are supposed to work in the parking lamps as well. Not sure about the marker lights though, but you will need the small dual filament bulbs (unless you have an alternative). Let me dig trough my receipts, I forgot where I got them.
These are the sockets (remove the tab). https://www.snydersantiqueauto.com/d...contact-socket
These are the bulbs (12v). https://www.snydersantiqueauto.com/s...rn-signal-bulb

As an aside, FMVSS-108 states:
S5.1.1.3 Intermediate side marker devices are not required on vehicles less than 30 feet in overall length. (These may be a combined lamp)
S5.4 Equipment combinations. Two or more lamps, reflective devices, or items of associated equipment may be combined if the requirements for each lamp, reflective device, and item of associated equipment are met, with the following exceptions:
(a) No high-mounted stop lamp shall be combined with any other lamp or reflective device, other than with a cargo lamp.
(b) No high-mounted stop lamp shall be combined optically, as defined by SAE Information Report J387 Terminology—Motor Vehicle Lighting NOV87, with any cargo lamp.
(c) No clearance lamp shall be combined optically, as defined by SAE Information Report J387 Terminology—Motor Vehicle Lighting NOV87, with any taillamp. (This can also be construed to include marker and clearance lamps to include turn signals).
Will largely depend on an officer's knowledge of the laws.

 

These conversion insulator discs are round and don't have the tabs to keep them from turning. The bulbs have the pins straight across so that they will work in the single filament sockets. And without staggered pins, I guess it is a 50/50 chance to get them in correctly. There are two insulator discs with each conversion kit, both have two holes for the wires. I guess you could take a dab of silicone and glue the bottom insulator into the bottom of the socket to keep them from turning as you installed the bulb. I guess I should have thought this out more before I had my grill powder coated. I probably could have removed the old bulb socket and modified the parking light to accept the plastic twist in sockets from a modern car.
Thanks fro the reply, Mark

 

Thanks for the info Bob, I will check with Snyders. I did a quick search earlier, and a couple of things I noticed, if I am reading correctly. First, I don't need an amber marker light at the front corner of the bed, like I thought I did, since the truck is less than 30 feet long. So, if that is the case, can I use an amber marker at the front corner as a turn signal only? Secondly, on one site I looked at, I think it was Trucklite, said that a side marker could also double as a turn signal, but not as a tail light. Maybe that is only referring to the center marker on long trailers. I had the holes in my fenders filled where the original owner had turn signals and I am really trying to avoid using the fender or cowl mounted turn signals.
Thanks again, Mark

 

No, you still need a light and reflector at the front and side-front of the bed (same for rear). This redundancy can be legally avoided by having a light at 45 degrees in the corner of the bed, and this only applies if the bed is wider than the cab (over 80"). You just don't need to have an intermediate light, but you can if you want, and it can be a combined marker/turn lamp. Sorry, you can't use combined marker/turn lights on the corners of the bed, if that's what you meant. If you're going to have West coast mirrors installed you can always hang a double faced pendant signal on them. Also, the front parking lamps would be legal for turn signals if they are at least 18" from the truck centerline.
I think I see where some confusion exists. "Combined use" also means a lamp that can also act as a reflex reflector. So if you have a light that acts as an approved reflector you don't need a separate reflector. I think TruckLite, Grote, and others have lamps that meet those specs.
I hear ya. I don't care for those fender mounted lights either.