Turn signals

[Dr. Bob]

Some months ago I swapped out my tail light and parking light bulbs for led in my '67 Barracuda with '68 grills as I prefer the look. Totally screwed up everything. Went back to bulbs, 1157 (front) and 1154 (rear) but now the only turn signal bulb that is working is passenger side parking light. I ordered a new '68 socket/cable for drivers side parking light as well as a new turn signal switch neither of which I have installed yet. Also, my turn signals do not cancel. When I took off the hub holding steering wheel on, I did not record where cancelling pin went so I put it at the 3:00 o'clock position and it does not work. I do not understand why drivers side parking light does not work when other 3 lights work, including the led headlights which I love. This is why I ordered a new cable/socket for drivers side even though when the led bulbs were in the car this light worked fine. No signal light but it was on when headlights were on. I understand for led to work I had to add some additional electrical components but I have decided to go back to the way the car was built and use the bulbs listed. I checked the fuses and all are fine. Checked the ground wire that attaches to the steering column retaining bolts and it is installed. I am not an electrician for sure and if I need to hire one, I am fine with that. But you know you have that feeling that some little thing is wrong and that is the feeling I have. Any help someone can provide will be most appreciated!! Thanks!

 

[67Dart273]

For starters do you have a service manual. If not wander over to MyMopar.com and download it for free, and also there are aftermarket wiring diagrams in the wiring section. These are not OEM, are not always complete as to options, and do not properly show the contour/ profile of connectors, but that are useful and sometimes easier to follow.

You should not be trying to use 1154 lamp, that is supposed to be 6V. Us 1157 all four corners.

I would start with tail, move to brake lamps, and move to turn signals. It is important to check that socket shells are grounded, that the shells and pigtail contacts are clean and free of corrosion.

What led you to replace the turn signal switch? Were the stock lamps not working previously?

 

[Murray]

Bulbs are 1034A front and 1034 rear, but you can use 1157. Canceling pin should be at the 9:00 position. Are both park lights grounded on the radiator support?

 

[junkyardhero]

i'd guess a combination of grounds and the turn signal switch.

sometimes if the switch is not installed properly it'll break in a way that can short or ground the lamps. so you're left with one hanging on or only brake lights.

 

[Mattax]

No signal light but it was on when headlights were on

Bob There probably is some SIW that occured in the swapping of parts.
The instrument panel indicator can be backfed a couple of ways. It could be somehting real simple like a bulb not properly seated, or a crosswire connection.

My suggestion is to test systematicly and write it down. Then the possible connections can be narrowed down.
1. Brake on/Brakes off.
2. Right turn/Left turn
3. Hazard on.
You can do further permutations if you want, but those are the basics. For example turn signal should overide that side's brake light.

1. Parking lights on
2. Parking lights on with turn signals right and left.
3. parking light on with hazards
If that doesn't replicate the issue then do it with the headlights on. Headlights should not in anyways effect the result but....

 

[67Dart273]

I don't remember the "trick" anymore but an example of backfeed at work:

You did something like this, and you didn't have the keys because Mom was shopping and you are in the car

You turn on the hazards, turn the signal lever one way or the other, and step on and hold down the brake pedal.

Then you can listen to the radio

 

[Inertia]

I don't remember the "trick" anymore but an example of backfeed at work:

You did something like this, and you didn't have the keys because Mom was shopping and you are in the car

You turn on the hazards, turn the signal lever one way or the other, and step on and hold down the brake pedal.

Then you can listen to the radio

It'd backfeed thru the flasher unit, so intermitant radio etc.