M1102 Bulb Question

[Tinwoodsman]

I picked up a M1102 trailer that is equipped with 24V bulbs. I replaced the front portion of the harness with a 7 pin round connector and cord wired directly into the connector under the bed. I have been searching various threads to find direct replacement 12V bulbs. There are many recommendations as to which bulbs to use but I have become confused and need help.

All bulbs in the trailer have double filaments and all bulbs have one terminal at the base. The tailight bulb and marker bulbs are ML 623 and the suggested replacement is the #67 but that is single filament. The turn indicator and brake light bulb is a GE 1683 and the suggested replacement is a #1156 but that is single filament also. The #1157 was suggested as a replacement and it is double filament but the retention pins on the base of the bulb are not directly across from each other and will not fit the socket. So, I am presently very confused. Besides identifying the correct 12V bulbs my questions are:

1. Do the replacement bulbs all need to be double filament? I assume the turn signal/brake light in the 24V #1683 provide separate illimunation but the bulb terminal is a single post.
2. I read in one post about the necessity for rewiring if the #1157 is used but it would not fit the socket anyway and the socket only has one wire coming into it.

I appreciate an help in clarifying which bulbs to use and exactly what rewiring would be necessary, if any.

 

[DeadParrot]

I think the military dual filament is for redundancy. The bulb will still work if one filament fails. The civy 12v equivalent doesn't have the dual filament backup.

#1 No, they don't need to be dual filament. Just made the same swap on my 101a1. It came with the later model 4 function lights. Use the 1156 for the 1683 and the 67 for the 623 and it should work just fine.
#2 The #1157 is a dual circuit bulb often used to combine both brake/turn and running/taillight functions into one bulb. It is easier to replace the entire socket then it is to modify a 1156 socket for an 1157 bulb. You shouldn't need to change anything but the bulbs per #1.

I don't know if there is a 12v dual filament version of either the 1156 or 67.