One more electrical issue to solve. My turn signals work great, brake lights blink with the turn signal on, but with the taillights on the filament for the taillights do not blink, making the turn signals in the back very hard for others to see when driving. You can see the one filament on the bulb flashing, but the other stays solid and seems brighter. Where should I look to fix this problem?

 

I assume you are talking about when your lights are on? If so. On my 64 the actual tail light filament does not blink. The brake/turn filament is the brighter of the 2 and will over power the taillight. I wonder if some where the wires are crossed sending turn signal power to the tail light filament and tail light power to the turn/brake filament? I believe on the 1157 bulb the filament that is higher in the bulb is the brightest filament which would be brake/turn

 

Thanks for the information, I think that's exactly what is happening. Now to figure out why...

 

Well...took both the lenses off and had someone hold the brake and turn the tail lights on. Both filaments seem to be the same brightness

 

I am assuming you are using an 1157 bulb? Brass base? Have you tried groundin the hosing to a good ground? That is all I can think of

 

I just realized but haven't posted yet. The bulb in there is NOT an 1157. I had to buy tail light assemblies from a 67 bronco because they had the back up light on the bottom. They came with bulbs preinstalled so I just slapped them in. Have 1157s now that I'm going to replace probably Monday. Thanks for all your help!

 

You may want to check the socket before installing the 1157 bulbs.
I also see a 2057 should work Model #2057, 12.8/14V, 26.9/6.7W

The 1157 bulb should have 2 contacts on the bottom, one for each filament, and to make sure the bulb gets installed right there are 2 pins that stick out on the brass part (the ground) that are at different heights.
The sockets should have 2 contacts in the bottom and where the pins fit should be at different heights.
I don't see how someone could install a non-1157 bulb and not hurt the sockets.

The back up light bulb should have one contact on the bottom for the one filament and the pins in the side should be at the same height.
The socket should match so look it over also. I am not sure what the back up light should be but want to say 67? but not sure.
Dave ----

 

Sorry for the confusion. The back up light bulb was separate, I was talking about the bulbs in the tail/ brake light socket. They are the same set up with the 2 pins. However it seems as if both the filaments receive the same amount of power, 12v and 5watts based off the side of the bulb. I will let everyone know how the 1157s work!

 

I know the back up light is separate & different than the tail / turn/brake light.

What was the bulb number that was in the tail / turn/brake light socket?
Dave ----

 

From what I could see there was no number marked. It reads 21/5w 12v 21/5w across the brass but that's about it. I'm taking that as both filaments are receiving the same amount of power, yeah?

 

Me too both would be 5 watts? don't know what the "21" is for? and it looks to be 12 volts.
Let us know how you make out.
Dave ----

 

An 1157 bulb is 27 watt. 8.3 watt. Candle power for the filaments is 32/3 there is the difference. If you can find 1157's with a brass base buy them. The ones with the siver base don't seem to be as good IMO.

 

Once bulb issue is sorted suggest test both legs of the bulb pins in the socket. Finally curious if the issue could be traced to a faulty flasher unit? Anyhow food for thought?

 

Same tail lamps and bulbs: 1967/72 F100/350 Stylesides; 1967/77 Bronco; 1969/74 Econoline.

Tail lamp bulb is #1157, #1034 also works, but there's a slight difference in the candlepower.