67 Dart Conv. - No Tail Lights, Park Lights, Flashers

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I don't understand the rewiring jump test. What happend to wire L8?
If there is power on B2, the rest should work with the switch on.
L1 connects to B1. It only powers the headlight terminal H. There is a 15 amp circuit breaker built in.
L8 connects to B2. It powers terminals P (L6), R (L2)and Inst (E1)in position 1, and R and Inst with headlights on.


First part means something inthe M2 circuit is grounding.
Is the headlight switch knob turned off of the dome light position?

Second part. What does the ammeter show?
Do the brake lights come on ?
I don’t jump to L8 because there was 12 volts there already, but only when the stop lamp switch was engaged(brakes). The only continuous power to the harness was the L1. I press on the brake and the L8 gets hot,
I release the brake pedal, then there is no voltage at L8. Not sure if ties to turn signal switch with D4A?
 
When something melts, its because the connection was damaged or weak, or too much current was drawn through it.
Too much current could be overwattage bulbs (unlikely in this case) or a short.

The damage here is on L1 wire terminal - and was due to higher wattage headlights (than the original 6012 bulbs) plus probably some oxidation and aging.

1707792998254.png


The little metal barb on the back of the teminal has to catch on the plastic. Otherwise the terminal backs out when the connector is attached.

1707793344849.png
 
I don’t jump to L8 because there was 12 volts there already, but only when the stop lamp switch was engaged(brakes). The only continuous power to the harness was the L1. I press on the brake and the L8 gets hot,
I release the brake pedal, then there is no voltage at L8. Not sure if ties to turn signal switch with D4A?
OK That's not right. L8 should always be hot. Power should come from L8 all the time. Key on or off.

D4A does go to the turn signal switch.
If the brake is applied and the turn signals are off, the power through the turn signal switch and to the brake lights.
If the brake is applied and a turn signal is on, that side brake light is disconnected.
 
When something melts, its because the connection was damaged or weak, or too much current was drawn through it.
Too much current could be overwattage bulbs (unlikely in this case) or a short.

The damage here is on L1 wire terminal - and was due to higher wattage headlights (than the original 6012 bulbs) plus probably some oxidation and aging.

View attachment 1716206424

The little metal barb on the back of the teminal has to catch on the plastic. Otherwise the terminal backs out when the connector is attached.

View attachment 1716206441
IMG_1044.jpeg


IMG_1043.jpeg
 
OK That's not right. L8 should always be hot. Power should come from L8 all the time. Key on or off.

D4A does go to the turn signal switch.
If the brake is applied and the turn signals are off, the power through the turn signal switch and to the brake lights.
If the brake is applied and a turn signal is on, that side brake light is disconnected.
What would cause L8 to only be hot when I push in the brake? The turn signal switch?
 
If, with Key off, stepping on brake pedal changes the voltage in L8, I'd suspect the horn wires as they are always hot.
If this only happens with the key on, then it could be turn signal wiring.

Maybe time to isolate stuff.
I would say start with disconnecting the brake switch, but I know it can be difficult.
Maybe the instead disconnect the column connector. Not fun either but with patience less difficult.
This should take any short in the column out of the picture.
Then see if L8 works normally.

1707794245091.png
 
Classic damage on the L1 at the B1 terminal. After you solve the mystery, consider a relay harness for the headlights. For some reason all the A-bodies have weaker headlight wiring than their bigger breathern. It was OK with 6012 bulbs but not the newer replacements.

Sometimes the wires at the dimmer switch and at the headlights themselves get hot too. They're only 18 gage on the A-bodies. Relay harness takes most of the power off these wires and uses them simply to trigger the relay in the engine bay.
 
What would cause L8 to only be hot when I push in the brake? The turn signal

Classic damage on the L1. After you solve the mystery, consider a relay harness for the headlights. For some reason all the A-bodies have weaker headlight wiring than their bigger breathern. It was OK with 6012 bulbs but not the newer replacements.
Okay. I appreciate you effort tonight, I will dive back into it tomorrow and check back with you. You been a solid resource and I appreciate the time you have spent this evening. Thanks again. Chris Parr here, what’s your name?
 
What would cause L8 to only be hot when I push in the brake? The turn signal switch?

I'm not sure quite what is going on but there are a couple scenarios.

Here's what should happen.
Close the switch and electrons flow from high energy 12 Volts through the bulbs and back to the battery ground, 0 volts.
1707795306874.png



Now lets say the horn wire H3 is cross wire shorting in the column or column connector.
H3 gets power from the battery.

If there is 12 Volts from the battery shorting to the brake light wire, then stepping on the brake pedal will make it show up in the rest of the line.
1707796215754.png


Just because there is 12 Volts that doesn't mean things will work.
With 12 volts on both side of something, electrons don't flow.
Its like taking the garden hose from the front of the house and connecting it to the hose in the back. There's pressure in both hoses but nothing moving.

Now back to the horn.
That relay has one power connection.
Wire H1-16V is always hot.
1707796610725.png

Wire H3 is also hot all the time.
When the horn button is pressed, it connects H3 to ground.
Current flowing from wire H1 to H3 powers an electromagnet. That electromagnet closes a switch connecting wire H1 to wire H2 powering the horns.

So H3 may be part of the problems here.
You could disconnect H3 at the relay and see if that returns some things to normal.
1707832744538.png


- Matt
 
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I'm not sure quite what is going on but there are a couple scenarios.

Here's what should happen.
Close the switch and electrons flow from high energy 12 Volts through the bulbs and back to the battery ground, 0 volts.
View attachment 1716206453


Now lets say the horn wire H3 is cross wire shorting in the column or column connector.
H3 gets power from the battery.

If there is 12 Volts from the battery shorting to the brake light wire, then stepping on the brake pedal will make it show up in the rest of the line.
View attachment 1716206456

Just because there is 12 Volts that doesn't mean things will work.
With 12 volts on both side of something, electrons don't flow.
Its like taking the garden hose from the front of the house and connecting it to the hose in the back. There's pressure in both hoses but nothing moving.

Now back to the horn.
That relay has one power connection.
Wire H1-16V is always hot.
View attachment 1716206457
Wire H3 is also hot all the time.
When the horn button is pressed, it connects H3 to ground.
Current flowing wire H1 to H3 powers an electromagnet that closes the switch connecting wire H1 to H2 powering the horns.

So H3 may be part of the problems here.
You could disconnect H3 at the relay and see if that returns some things to normal.

- Matt

Awesome job Matt!!

I'm sure I as well as others following along learned a lot from your diagnostics.

Well done!!
 
If, with Key off, stepping on brake pedal changes the voltage in L8, I'd suspect the horn wires as they are always hot.
If this only happens with the key on, then it could be turn signal wiring.

Maybe time to isolate stuff.
I would say start with disconnecting the brake switch, but I know it can be difficult.
Maybe the instead disconnect the column connector. Not fun either but with patience less difficult.
This should take any short in the column out of the picture.
Then see if L8 works normally.

View attachment 1716206447
Hi Matt - Wanted to folllow up with this scenario. I have miss spoke about L8, but here is what I have. With the steering column harness connected, L8 is hot only when the door is shut. L8 is hot with the door shut until the brake is applied, then goes to zero volts. The same happens with the steering column harness disconnected, with the exception of the stop light switch being engaged has no effect. All checked at the headlight switch harness. Steering Column harness disconnected, door shut, key off the voltage at L8 is 12.2v, turn the key to the accessory position it drops to 11.5v. Checked at the fuse box at the dome stop and tail location with the fuse out and i get power (12.2v) on one side, the mounting screw side. I think this is telling me that the problem is not in the column.
 
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Here's an overall view of these things connecting
View attachment 1716206395

Emergency flasher on my '67 Barracuda.
View attachment 1716206396

^Instrument Panel removed and camara view looking through to the left side^
Wire routing on the Dart is different but I think the fusebox, brake switch and flasher units are all in the same locations for Dart, Valiant, and Barracuda
I checked for the emergency flasher and there is no unit or mounting bracket it like shown here. I bought and installed aftermarket one. (Novita 2 Terminal, 12-Volt Long Life Hazard Warning and Turn Signal Flasher)
 
L8 is hot with the door shut until the brake is applied, then goes to zero volts.
Did you note how much current the ammeter was showing when you did this?
and
Steering Column harness disconnected, door shut, key off the voltage at L8 is 12.2v, turn the key to the accessory position it drops to 11.5v.
this?

If volts go to zero at point of measurement, and the ammeter shows discharge, then current is flowing and there is a short or connection to ground before the point of Voltage measuremnt. The ammeter scale is roughly 40 amps at full discharge and 0 in center. Estimate based on that.
 
Checked at the fuse box at the dome stop and tail location with the fuse out and i get power (12.2v) on one side, the mounting screw side.
1708085933755.png


Here's the top view with the dust and water shield removed.

You measured on the supply side of the fuses. So that confirms power is present in the power supply feed.
1708101678818.png
 
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Did you note how much current the ammeter was showing when you did this?
and

this?

If volts go to zero at point of measurement, and the ammeter shows discharge, then current is flowing and there is a short or connection to ground before the point of Voltage measuremnt. The ammeter scale is roughly 40 amps at full discharge and 0 in center. Estimate based on that.
I will check this. What would cause the L8 to loose all voltage
View attachment 1716207703

Here's the top view with the dust and water shield removed.

So you measured on the supply side of the fuses.
View attachment 1716207768
I will check this and report back, yes I measured on the supply side. L8 powers M1(Left front door automatic switch) the door switch and back to the D terminal throught M2? What would cause L8 to loose power when shutting the door? Thanks again for the help on all this.
 
Steering Column harness disconnected, door shut, key off the voltage at L8 is 12.2v, turn the key to the accessory position it drops to 11.5v.
I beleive something is going here causing current to flow.
The ammeter would confirm that.

If all the circuits were intact with no shorts, turning the key to accessory should do nothing as long as everything is off.
But if something was on, then normally we could be pretty sure there was a poor connection between the battery and the mains splice.
1708103192911.png


However we know something is cross wired or shorting, so we'll have to come back to this.
Next break I'll look at the other test results.
 
The weird part is that the courtesy lights stay on when the door is closed and dim them the brake is applied.

I will check this and report back, yes I measured on the supply side. L8 powers M1(Left front door automatic switch) the door switch and back to the D terminal throught M2? What would cause L8 to loose power when shutting the door? Thanks again for the help on all this.

These really point to something related to the courtesy/dome light circuit shorting or backfeeding.
That's why I want to study that a little more and hopefully we can narrow down where to look.

How did you disconnect the horn so it wasn't blowing constantly?
 
These really point to something related to the courtesy/dome light circuit shorting or backfeeding.
That's why I want to study that a little more and hopefully we can narrow down where to look.

How did you disconnect the horn so it wasn't blowing constantly?
I disconnected the horn at the horn relay switch.
 
Did you note how much current the ammeter was showing when you did this?
and

this?

If volts go to zero at point of measurement, and the ammeter shows discharge, then current is flowing and there is a short or connection to ground before the point of Voltage measuremnt. The ammeter scale is roughly 40 amps at full discharge and 0 in center. Estimate based on that.

Both connectors?
 
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