67 Barracuda Turn Signal Dielemma

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Ken Pevay

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My name is Ken and I'm new to this forum, wondering if anyone has come across this one. I have an issue that has popped up on my recently purchased 67 Barracuda Convertible. Turn signals work fine with headlights off. With headlights or parking lights on the the dash indicator for the left turn signal is always on unless you activate the left turn signal in which case it will flash in the normal fashion until its shut off and it returns to the stay on status with the lights on. Shut the lights off and it goes out. The previous owner had the instrument cluster was professionally restored. This is a recent development and wasn't doing this the first time i drove the car at night. I have only had the car for a little over a month and only drove it twice as I live in Massachusetts salt country this time of year.
Barracuda.jpg
 
Well Ken, welcome to FABO. I cant help you with your dash problem but i can tell you that your car is BEAUTIFUL!!!
 
Ken. I hope you like puzzles! :)
This one shouldn't be too difficult.
It sounds like the parking light was a cross wire short to the turn signal.

There's an explanation of the turn signal, stop and hazzard circuits here:
1967 Chrysler Imperial Electrical Accessory Circuit From the Master Technicians Service Conference Session 236

A little explanation about the schematic they use.
The portions I've colored represent the moving brass contacts in the turn signal switch. All three move together when the signal lever is moved.
The black circles are connected to the wires and do not move.
upload_2019-4-17_18-11-52-png.png


Might check whether one lamp is weak which would be another clue as to where a short gould be occuring.

Current flow with parking lights should be along the dashed paths.
upload_2021-1-8_17-44-19.png


Something like this is going on.
upload_2021-1-8_17-46-41.png


I'd probably check the bulb and the socket and wiring.
Do a search for posts about removing the parking lamps on a '67 Barracuda to get a sense of how its accessed.
 
Parking light position on the headlight switch also turns on the instrument illumination lamps. But offthe top of my head I dont think as likely to result in what you're describing.
 
here's a couple pics from the last time I had one off
upload_2021-1-8_17-58-36.png


upload_2021-1-8_17-59-35.png
 
Well Ken, welcome to FABO. I cant help you with your dash problem but i can tell you that your car is BEAUTIFUL!!!
Thanks I'll be around this where I belong, I was brought up in a Mopar only house, A 67 Mustang Convertible got me into the hobby as an adult, Followed by a 66 Pontiac Lemans, back to my roots my teenage car was a 63 Valliant Convertible.
 
When weird stuff like this happens, it is often a missing ground somewhere. Look at the brightness of all your lamps when they are on. That can be a clue.
 
Parking light position on the headlight switch also turns on the instrument illumination lamps. But offthe top of my head I dont think as likely to result in what you're describing.
Thanks so much for taking the time to respond. I have had the parking lights off and apart new bulbs etc... rear bulbs are new as well. turn signal lever is a little floaty my first step will be to remove the steering wheel and start with the switch. I'm sure it will be a puzzle. I also have to investigate the gas guage/sending unit on my first test ride after the car arrived guage had dropped to almost "E" stopped and filled it up and only took a little less than 5 gallons. as the dash gage went from full to almost 1/2 tank after only 20 miles after the fill up there seems to be something ging on with the sending unit. thanks again for your help.
 
Some pics of the lemans when you have chance. I like the early ones particularly. Pontiacs had good looks and instruments which I liked.

You must know by now in the old car world new is not always good or right. :( Sometimes it is, sometimes not.

Correct bulbs?

Off the top of my head shouldn't be in the turn signal switch.
That switch doesn't even get power when the key is off.
A check could be made for that and or a back feed at the column connector.
You have the Barracuda supplement?
There's also pdf of that diagram here by @1969383S
1969 Plymouth Barracuda wiring diagram (not mine)
Make sure you got the '67. There are small changes each year.

This gets back to Mike's point about grounds.
Lets say the ground for one or both of the front parking lamps is weak or loose.
upload_2021-1-8_18-47-45.png


Then the next easiest path for electricity to flow is through a turn signal indicator.
Something like this.
upload_2021-1-8_18-52-45.png


That's another reason to see how the outside lamps are working or not under each situation.
 
Thanks so much for taking the time to respond. I have had the parking lights off and apart new bulbs etc... rear bulbs are new as well. turn signal lever is a little floaty my first step will be to remove the steering wheel and start with the switch. I'm sure it will be a puzzle. I also have to investigate the gas guage/sending unit on my first test ride after the car arrived guage had dropped to almost "E" stopped and filled it up and only took a little less than 5 gallons. as the dash gage went from full to almost 1/2 tank after only 20 miles after the fill up there seems to be something ging on with the sending unit. thanks again for your help.

The gas gauge behavior is typical of aftermarket fuel senders. Lots of threads on this.
 
Yes, check the grounds for both the front and rear lamps. The pins in the multi connector on the back of the dash are also a suspect, but you say the dash was already restored. Still... maybe a good idea to make sure the instrument panel ground wire is attached, at least. There is a also a steering column ground wire that might affect the turn signal switch if missing.

As for the fuel gauge, it contains the voltage regulator for the instrument panel, so that is a possible connection. But if the PO installed a replacement aftermarket sender unit, you may just have to live with an inaccurate reading — the ones they sell as replacements are not calibrated for the A-body fuel tank and cannot be adjusted to be accurate over the full range.
 
Yes, check the grounds for both the front and rear lamps. The pins in the multi connector on the back of the dash are also a suspect, but you say the dash was already restored. Still... maybe a good idea to make sure the instrument panel ground wire is attached, at least. There is a also a steering column ground wire that might affect the turn signal switch if missing.

As for the fuel gauge, it contains the voltage regulator for the instrument panel, so that is a possible connection. But if the PO installed a replacement aftermarket sender unit, you may just have to live with an inaccurate reading — the ones they sell as replacements are not calibrated for the A-body fuel tank and cannot be adjusted to be accurate over the full range.

I have used a meter match successfully to improve the accuracy of the aftermarket senders. Other than getting a rebuilt oem sender, that is your only choice other than living with it.
 
Some pics of the lemans when you have chance. I like the early ones particularly. Pontiacs had good looks and instruments which I liked.

You must know by now in the old car world new is not always good or right. :( Sometimes it is, sometimes not.

Correct bulbs?

Off the top of my head shouldn't be in the turn signal switch.
That switch doesn't even get power when the key is off.
A check could be made for that and or a back feed at the column connector.
You have the Barracuda supplement?
There's also pdf of that diagram here by @1969383S
1969 Plymouth Barracuda wiring diagram (not mine)
Make sure you got the '67. There are small changes each year.

This gets back to Mike's point about grounds.
Lets say the ground for one or both of the front parking lamps is weak or loose.
View attachment 1715666384

Then the next easiest path for electricity to flow is through a turn signal indicator.
Something like this.
View attachment 1715666394

That's another reason to see how the outside lamps are working or not under each situation.
I just ordered the supplement yesterday, believe it or not i had the 67 Plymouth manual from the early 70's when my dad got it for a car we had in the family. He worked for chrysler as a rep and got me manuals for every car I had which I still have, 60 Desoto, 63 Valliant, 66 Plymoiuth, 67 Plymouth, 69 Plymouth, 72 Charger, and I also have a 1960 Desoto Parts book. Thanks for taking the time to respond.
 
When turn indicator comes on with park lamps, the fault is lack of chassis ground at that front turn signal. fixtures on front of 67 have a bulb socket crimped into a cast metal housing ( no actual ground wire ). Fault has to be corrosion inside bulb socket or socket loose at the crimp to fixture. This fault cannot happen at rear fixtures. Park circuit current doesn't have a complete path back to the turn indicator, due to turn signal switch.
A addon part called meter match will correct your fuel gauge.
 
I just ordered the supplement yesterday, believe it or not i had the 67 Plymouth manual from the early 70's when my dad got it for a car we had in the family. He worked for chrysler as a rep and got me manuals for every car I had which I still have, 60 Desoto, 63 Valliant, 66 Plymoiuth, 67 Plymouth, 69 Plymouth, 72 Charger, and I also have a 1960 Desoto Parts book. Thanks for taking the time to respond.
There's some pdf versions of the supplement floating around. Might be at Hammtramk Historical library or maybe mymopar.
Advantage is you can print and mark up! So nice to have both.
 
When weird stuff like this happens, it is often a missing ground somewhere. Look at the brightness of all your lamps when they are on. That can be a clue.
Bingo! Found a bad ground between the parking light housing and the bulb socket. Thanks for your help.
 
Some pics of the lemans when you have chance. I like the early ones particularly. Pontiacs had good looks and instruments which I liked.

You must know by now in the old car world new is not always good or right. :( Sometimes it is, sometimes not.

Correct bulbs?

Off the top of my head shouldn't be in the turn signal switch.
That switch doesn't even get power when the key is off.
A check could be made for that and or a back feed at the column connector.
You have the Barracuda supplement?
There's also pdf of that diagram here by @1969383S
1969 Plymouth Barracuda wiring diagram (not mine)
Make sure you got the '67. There are small changes each year.

This gets back to Mike's point about grounds.
Lets say the ground for one or both of the front parking lamps is weak or loose.
View attachment 1715666384

Then the next easiest path for electricity to flow is through a turn signal indicator.
Something like this.
View attachment 1715666394

That's another reason to see how the outside lamps are working or not under each situation.
Found a bad ground between the parking light housing and the bulb socket. nothing a small bead of solder between the housing and the socked couldn't take care of. this also explains the hose clamp with a peice of wire broken off on the other side, must have been the same problem at some point in time. Needless to say I added a bead of solder on that side as well. Thanks for your help. Below are a few pics of my Pontiac. Opted to sell too much knee pian with the clutch. I was a 326, two speed power glide with a 273 differencial. It left me as a 400 4 bbl, 4 speed, 323 posi.
IMG_7212.JPG
IMG_7228.JPG
 
Beautiful! Love the boxy Pontiacs!
Found a bad ground between the parking light housing and the bulb socket. nothing a small bead of solder between the housing and the socked couldn't take care of. this also explains the hose clamp with a peice of wire broken off on the other side, must have been the same problem at some point in time. Needless to say I added a bead of solder on that side as well. Thanks for your help. Below are a few pics of my Pontiac. Opted to sell too much knee pian with the clutch. I was a 326, two speed power glide with a 273 differencial. It left me as a 400 4 bbl, 4 speed, 323 posi.View attachment 1715667599 View attachment 1715667598
 
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Found a bad ground between the parking light housing and the bulb socket. nothing a small bead of solder between the housing and the socked couldn't take care of. this also explains the hose clamp with a peice of wire broken off on the other side, must have been the same problem at some point in time. Needless to say I added a bead of solder on that side as well.
I've seen the solder in the crack tried before. It wont work long term. I dont know why solder doesn't bond well to the cast pot metal but it doesn't. Vibration will cause do over and over. Solder a wire or a male tang for a female wire terminal onto the outside of the socket. Or just buy another fixture. Without good lens and bezel shouldn't cost too much.
 
I've seen the solder in the crack tried before. It wont work long term. I dont know why solder doesn't bond well to the cast pot metal but it doesn't. Vibration will cause do over and over. Solder a wire or a male tang for a female wire terminal onto the outside of the socket. Or just buy another fixture. Without good lens and bezel shouldn't cost too much.
Thanks for the feedback, I'll keep a watch on it. I did prep the surfaces with my dremmel and figured if it doesn't last I would do just what you suggested.
 
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