Progress made, but still no brake light on left

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abgwin

abgwin

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Finally finished installing the new turn signal switch on my 66 Barracuda, which solved quite a few problems: turn signal now works correctly, steering wheel has all its pieces and doesn't flop around when turning, signal even turns off when you turn the wheel and the horns haven't turned themselves on spontaneously.

However, still some problems. The left brake light doesn't work, though I know the bulb is good since the turn signal works.

Since I only reconnected wires based on what the previous owner had done, does this suggest one (or more) of them are swapped?

Any advice appreciated.
 
new bulb, clean the socket, and check your grounds.if one side of the brake lights work, its not the brake light switch
 
If I'm not mistaken, the brakes and turn signal use the same filament, as the turn signal interrupts the brake on the side of intended turn.

The parking light (dimmer filament) also works, as do all parking lights at the other corners.
 
abgwin said:
If I'm not mistaken, the brakes and turn signal use the same filament, as the turn signal interrupts the brake on the side of intended turn.
Click to expand...

Correct, although the bulb "looks" good it may not be, have you tried a different one?
Double check your ground on that side.
Does the brake light on that side work?
Double check the socket.
Switch the bulb to the other side and see if the problem goes with it.
 
Try wiggling the turn signal switch a little bit while stepping on the brake pedal with someone watching.
I had this problem with a new aftermarket switch and figured it out with two way radios with my buddy following me to a car cruise.

For some reason after wiggling the turn signal switch lever back and forth a bit it seemed to fix the problem and I have not had any problem since.
 
The stop (brake) light function and the turn signal function use the same filament, the bright 27w one. The dim 8w one is only for the tail light function. Yours is a very strange set of symptoms -- the power path for the left brake light is identical to the power path for the left rear turn signal, except within and upstream of the turn signal switch. Weird symptoms like this are often traceable to poor grounds, and in many cases it's difficult to imagine the bizarre "by way of Topeka" current paths that result from a faulty ground. Checking the quality of grounds is usually a wise early step in diagnosis of a problem like this.

But the symptom you have (one brake light doesn't work, turn signal works) is most frequently the result of a faulty turn signal switch. Where'd you get your new one, is it one of mine, or a Chinese special?
 
The turn signal is the one I bought from you. I believe that I've connected the switch wires correctly, but not 100% due to the previous owner's haphazard splices and difficulty matching the wires by color.

I would think that the ground for the left turn signal would be the same as the ground for the left brake, but electrical issues are my weakest point.

I can say that the switch is remarkably stiff, feels like I'm nearly breaking it to activate the turn signal.
 
abgwin said:
I can say that the switch is remarkably stiff, feels like I'm nearly breaking it to activate the turn signal.
Click to expand...

I would look it over again. I had the same issues with my car and all of my problems were resolved right there in the turn signal switch. I had to pull it apart several times before I got everything working properly.

I would check the grounds again on that side to be sure.
 
abgwin said:
he switch is remarkably stiff, feels like I'm nearly breaking it to activate the turn signal.
Click to expand...

The screw that holds the lever to the switch is too tight. Back it off about 1/2 turn and see if that solves the problem; the switch may be binding and not allowing the internal contacts to move to their correct position in the neutral (no turn) position.

If you try to take the switch apart, you will likely have great difficulty (at best) putting it back together.

If no luck just by unbinding, since the problem has persisted across two different turn signal switches, and you say the wiring was hacked, I think I would take a hard, careful look at all the wires before trying another switch (that said, I'm out of switches, but if it turns out I sent you a bum switch, I'll replace it when I get more).
 
We just had the same problem; backed out the 3 screws, and it worked. It looked like it was cancelling, but not quite enough.
 
green1 said:
We just had the same problem; backed out the 3 screws, and it worked. It looked like it was cancelling, but not quite enough.
Click to expand...

Which three screws? The horn retainers or the ones that hold the turn signal switch?
 
Start with the one screw that holds the turn signal lever to the switch. Illogical as it may seem, it should not be tightened down firmly or things won't work right. If that doesn't cure the problem, slightly loosen the three screws that hold the turn signal switch to the steering column body.
 
OK, have tried both. It did improve the turn signal switch's action, but didn't result in a left hand brake light.
 
After looking at the wiring diagram, i can't understand how it could be a grounding issue. The turn signal and brake signal are the same wire to the bulb, so if there were a grounding problem, I shouldn't get a turn signal - but I do.

I have a right hand brake light, so it's not the brake switch.

The wire to the left hand bulb is intact, or I wouldn't have turn signal.

Is there any way to test the turn signal switch? I just can't think of anything other than the switch being the culprit.
 
did you take the bulb out of the right side and try it in the left side? each bulb socket has to grounded. some times it takes a few twists with the bulb to get a good connection. from my lighting dilemmas (and i have had my share believe me) , the odds of two different signal cancellors having the same issue are against you. i have had many brake light/running light and signal issues and 90% of them have been bad grounds, corroded/worn out sockets and bad bulbs.
 
To be absolutely sure, remove the left kick panel and find the connector that separates the dash side of the harness from the rear harness going to the rear, under the sill plate.

"Rig" (everybody should have one) a junk socket with a tail/ stop bulb and twist both wires together. This will form a good heavy load, and show up bad connections in the column switch/ brake light switch/ fuses, etc.

Find the left and right turn signal conductors, and clip to 'em one at a time

You have a shop manual?

Download one here:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download

Direct link (comes from MyMopar)

http://www.mymopar.com/downloads/servicemanuals/1966_Plymouth_Service_Manual.zip

or the "not quite as good" diagrams from the same place:

http://www.mymopar.com/downloads/1966/66BarracudaA.jpg

http://www.mymopar.com/downloads/1966/66BarracudaB.jpg


Those diagrams show the left and right turn wiring as DARK GREEN and BROWN

If you have turn on the appropriate wire and no brake, but you have BOTH turn and brake on the other side, it HAS to be the column switch
 
abgwin said:
After looking at the wiring diagram, i can't understand how it could be a grounding issue. The turn signal and brake signal are the same wire to the bulb, so if there were a grounding problem, I shouldn't get a turn signal - but I do.

I have a right hand brake light, so it's not the brake switch.

The wire to the left hand bulb is intact, or I wouldn't have turn signal.

Is there any way to test the turn signal switch? I just can't think of anything other than the switch being the culprit.
Click to expand...

Can you post a pic of the switch in the column? Not sure it will help, but maybe somethings missing or out of place that someone can pick up on. Just a thought.
 
Badsport said:
Can you post a pic of the switch in the column? Not sure it will help, but maybe somethings missing or out of place that someone can pick up on. Just a thought.
Click to expand...

PICT0848.jpg


Finally have the front right hub/brake sorted, so will return to work on this.
 
Under that top piece, if it's like mine, was a flat bar that makes contact on the top and bottom. When I put my switch in somehow I disturbed that which in return caused some unusual issues. Double check that.

If that bar is there, there is a slot top and bottom that it rests in. Mine popped out of one of the slots.
 
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