Left tail lite, bright, right one, very dim. 47 Dodge

[central52]

On my 47 Dodge, the left,driver's side tail lite is bright, but the right side, passenger, shows a dim lite. I changed the bulb with a new bulb, cleaned the contacts with a wire brush, and wire brushed around the unit that goes into the fender.  Could it be old wiring, but yet the left shows bright.  Same wiring, I think, no?  I hate to think I have to change the whole wiring from dash to lite.  Any ideas?  Ed

[Merle Coggins]

Is it a dual filament bulb (tail/brake)? If so is it indexed properly? Try turning it 180 degrees in the socket.

[desoto1939]

it also could be a ground issue. hook a good wire to the light socket and then run the wire to a very good clean bare metal spot maybe on the frame. See if the light get brighter then it would be a ground issue. As another person stated the bulb might be insert incorrect and indexed the wrong way.

 

Rich Hartung

[Ulu]

What rich sez, except just run a wire right to the ground of the light which works OK. They're close enough you can hold both ends & see if the weak light gets brighter.

 

If not, check the voltage to the two teminals. Sometimes the little brass contacts, which are soldered to the wires, corrode in the solder joint & develop resistance. If so you'll measure a low voltage there instead of the desired 6.3v.

[Darbone85737]

The power for both rear lights goes from the front of the car to a bar on the driver's side front of the trunk.  From there two separate wires go to the left and right sides, so if only one side is dim the problem is somewhere in the trunk.  I would agree with the suggestion to check the ground on the dim side.  

Edited May 8, 2015 by Darbone85737

[Oldguy48]

I had a similar problem with my P15. I drilled a hole in the spring clip that attaches the bulb socket to the fender, and installed a jumper wire to one of the tail lamp mounting screws to provide a better ground. That spring clip depends on spring pressure to achieve a ground connection to the fender, and any rust/corrosion/ paint/ etc. between the spring clip and the fender can result in a voltage drop to the bulb, which results in a dim bulb. And if you try this, use a star washer under the terminal lugs. It will help to make a better connection.

[central52]

Great information, you're right about indexing the filament bulb, turned it around, and got a much better lite. And now I'm going to do that ground wire thing to improve the connection. Those little tips in the socket sounds like it also could be better, where can I buy them? Thanks, guys. Ed

Edited May 9, 2015 by central52

[Merle Coggins]

Now I have to ask, If you turned around the dim one and now it's bright, what happens when you activate the brake lights? If they are dual filament bulbs they are likely tail/brake lights, or tail/turn lamps. The dimmer filament should be the tail lamp and the brighter one is the brake and/or turn signal. 

 

Merle

[Darbone85737]

Merle has a point. If you reverse the wires for the tail & brake lights that side will be brighter than the other.  I don't think you can index the bulbs wrong in the socket because of the differing heights of the pins

[Don Coatney]

Merle has a point. If you reverse the wires for the tail & brake lights that side will be brighter than the other.  I don't think you can index the bulbs wrong in the socket because of the differing heights of the pins

Not all dual filament bulbs and bulb sockets have staggered pins. 

 

[BigDaddyO]

Not all dual filament bulbs and bulb sockets have staggered pins. 

 

non staggered pins.jpg

Well they should...

[T120]

Not all dual filament bulbs and bulb sockets have staggered pins. 

 

non staggered pins.jpg

In my 48 Dodge,(6 volts),the pins are in the same plane -1158 dual filament bulbs.It requires checking the operation of the tail light and turn signal function,(brighter) when the bulbs are replaced.

Edited May 10, 2015 by Ralph D25cpe

[Niel Hoback]

Same thing on my 48 P-15. Can be had at an Amish buggy supply store.

[Don Coatney]

Well they should...

Of the many things I have control of in my life that is not one of them. Perhaps you should start a movement to correct this.

[Plymouthy Adams]

_{the staggered bayonet base/socket came later as the standard dual element socket was standardized.} 

 

_{also there were two common staggered bayonet bulbs of the early period that had different candlepower (current draw. been long time, thinking 1034 and 1157) where if you mix and matched the bulbs..brilliance and flasher rate could vary side to side...that is why you must verify what you need or at minimum match the bulbs...}

 

_{there is a certain amount of user common sense needed when user intervention is applied to daily maintenance...not calling anyone stupid mind you..only that you need be aware...while often common not to know what may be need in relamping the older cars due to few in depth owner's manuals...common sense to balance the circuit}

[Don Coatney]

Amazing the trivia one recalls. I learned of 1034 and 1157 12 volt bulbs when I was about 12 years old hanging out at the neighborhood gas station.

[BigDaddyO]

Of the many things I have control of in my life that is not one of them. Perhaps you should start a movement to correct this.

I'm not that invested in it. I just think they should be.

[Darbone85737]

I only made the comment because the ones in my car do have staggered pins, but they are obviously not standard for the car

[White Spyder]

Thought you were looking at 6v led's.

[central52]

Neil, where is that Amish buggy supply store you mentioned? Lot of Amish stuff on the internet. Ed

[Niel Hoback]

I get my stuff at Yoder's in Shipshewanna, IN. They might do online? I don't know. Lehman's has couple of stores in Ohio that I think does online stuff, but they are mostly non-electric appliance and home decor.