The Stovebolt Site Forums The Shop Area The Electrical Bay Bulb and socket question - 1954 GMC

So while checking my lights I found that the aftermarket sockets that have the oval plastic piece can come out of the metal case and once they are out of case the plastic can go back in two ways .The problem with that is if it is flipped around the contacts get flipped also so this can result in your brake light turning to a running light .I have the running lights lighting on the front filament of the bulb and same on the front.My question is does anyone know which filament on a 6 volt 1154 bulb is the bright(brake light )(or front signal ) and which is the running light filament .

I looked up the 12 volt version of a 1154 bulb 1157 and it looks like the thicker filament is the turn and stop and the smaller the running lights so it looks like I had it correct .Thanks Kevin

I've never checked a 1154, but on the 12 volt dual filament bulbs the element that is further into the glass is the brighter.

Both the 1154 and 1157 bulbs have offset pins so they only go in the socket one way. But the wiring could be flipped so that the brighter filament is connected to the tail light circuit. It's just a matter of how the pigtail is wired. You'd have to apply 6V to each contact on the bulb to check which is the brighter filament and then wire the socket correctly.

Yes the bulb goes in one way but I was pointing out that when the bulb is out the plastic insulated piece can pop out of the metal and once out it can turn and go back in opposite resulting in the bulb contacts being opposite .I was almost ready to cut and resolder the wires when I noticed this.

Until I find a better socket that will clip on the back of my signal light I think I will put a dab of jb weld to hold the plastic from coming out of the metal that will keep the contacts from getting reversed .There is a dimple in the plastic but no corresponding bump in the metal to make sure it goes in the proper way. Now to get the signal lights working .

Bummer to hear you're having such difficulties with the light sockets. Sounds like you've got a working solution to fix the problem. Appreciate your sharing as it may help others out if/when they run into a similar situation.

Every now and then you see an older vehicle with a bright running light but not to brighter when they step on the brakes .The after market sockets like I have are easy for this to happen when you go to change a bulb. Yes it is a easy fix or even just to be aware that the insides can twist around ,but once it twists it is hard to determine it is proper until you turn the light on to check.On a good note I was able to sneak a screwdriver up to the squirel cage in the heater to move it over so it does not catch the case ,now the fan blows nice and quiet.

Here's what I did for my front bulbs. I use 2 of those bulbs on the left. I wanted bright turn signals and got them.

This shows the sockets.

That is a good fix especially with the led 12 volt .Unfortunately my truck is a 54 and two sockets won’t fit wonder the lens but I may further down the road try some led bulbs .