Odd bulb type

[Britcarguy]

In the process of converting to LED lighting I ran across one bulb I cannot identify. On my 2000 Damon Intruder all the lighting is 1156 or what they call BA15 socket now. Easy swap, except for some bad China bulbs which is another post later. On the wall light by the bed and the wall lamps by the couch I found a bulb with 1157 staggered bayonet lugs and a single center contact like an 1156. The glass bulb is about 3/4 what a standard 1156/7 glass would be. What is this? I can't find it on any standard automotive bulb table?

[Britcarguy]

Thanks Chris, that is what I have learned. BAY15D is the 1157 w/dual element/dual terminal and staggered lugs, there is a BA15D which is the 1004 which is also dual terminal but signal element, but with straight across posts. I think a lot of confusion could have been avoided if the two where not so closely named (BAY15D vs BA15D). Didn't know about the polarity, thought the 1004 had two positive and a socket ground, your explaination makes more sense .

[Dr_Quick]

I would just file or grind off one of the lugs on a 1157 and see if that would work. Probably compare 1157 to new bulb to see where lugs are located and decide which one needs to go.

[Chris_Bryant]

The 1004 and 1076 are dual contact single filament bulbs- they do not ground through the base- one contact is hot, the other ground. They are most commonly used in wall sconce type fixtures. The 1004 has a small glass envelope, the 1076 has a normal sized glass.

[wa8yxm]

Single contact lamps should not have staggered lugs,, Take a look at the socket and see if the slots are staggered or if someone forced an issue.

DOUBLE contact lamps have staggered lugs.

[oldbeek]

Sounds like someone changed the pig tail in the lamp. Why not get an 1157 replacement and run solder between the 2 contacts on the bulb.

[nvreloader]

FYI
The GE 1004 bulb is also used in the Sears router, lights up the cutting area, just changed out mine to quit working.

Tia,
Don

[Britcarguy]

You are correct about the pins, that is what was so confusing on this. Thanks, I did find the tiny print and the bulb is a GE 1004. It has two contacts like 1157, but lugs are not staggered so in that respect it is like 1156. A 1004 is probably lower lumin and not to auto taillight standard for output.
Many thanks to all helping solve this.

[enblethen]

What is the lamp number that is in it? Should be marked on base or on glass(hard to read)
Single filament do not have offset pins. Dual filaments have offset.

[beemerphile1]

I've never seen what you described. The reason for the offset pins is to insure correct orientation in the socket. If the lamp is only a single contact there is no wrong orientation.

[Britcarguy]

I did find a picture of the 1003, it has bayonets like an 1156 ( straight across from each other). That won't work. Very odd, thought I had seen every automotive bI'll around.

[Britcarguy]

Thanks, so your saying the "1003" base does have the offset locking bayonets?

[enblethen]

There is different lamps and shapes based on candle power output.
Sounds like yours could be a 1003. Single contact single filament.
1003