Headlight Switch Cranks Engine??

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May have had some mice gnaw away insulation at some point in the previous 47 years. That will cause shorts/crossed wires. I don't think these things often go bad without an outside influence. Maybe someone has worked on it before, and messed something up. That's often the case. Removing the radio, and heater controls helps alot to access the under dash wiring.
 
Follow the wire from the starter solenoid back into the cabin.

Mine had melted to the positive ammeter wire, thus providing the 12 volts needed to turn the car over. Pretty easy to find if you know what your looking for.
 
20190115_090405.jpg
Here is a pic of the starter relay. Pretty sure the yellow wire actuates the solenoid. So disconnect this one, hook a voltmeter to it, and turn on the headlites. If it goes to 12 V with lights on, trace back to see where it connects to the headlites on wire. Usually would be near or at the switch. But really could be anywhere.
 
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Garys72Duster said:
View attachment 1715276050 Here is a pic of the starter relay. Pretty sure the brown with yellow tracer actuates the solenoid, with the pink insulator. So disconnect this one, hook a voltmeter to it, and turn on the headlites. If it goes to 12 V with lights on, trace back to see where it connects to the headlites on wire. Usually would be near or at the switch. But really could be anywhere.
Click to expand...
The brown is your neutral safety, the yellow is the ignition.


Alan
 
Garys72Duster said:
Oh ok, thanks. So voltmeter to yellow wire, turn on headlites, see if voltage jumps to 12 volts.
Click to expand...
Gary: Are you trying to solve your problem or Manny's (the OP)?
Be easier to do these one at a time - even seperate threads would be good.
Its almost a given one of Manny's headlight wires is contacting the start wire to the relay, especially if it only happens when the headlight switch causes the starter to turn when the headlights are on. If it happens when parking lights are on, then its a wire in that circuit (or instrument illumination).

Do yourself a favor and download the Dodge Service manual for your year. Then you'll have the best reference for colors etc. It still may have mistakes but less than the non-factory diagrams like those on mymopar.

For your problems with the signal and marker lamps take a look at the guidance from Tech. Using the FSM wiring diagrams, make a schematic - it may be the same as one of those shown in the Master Tech booklets, but it may be a little different.

1973 Chrysler Electrical System, Master Technician's Service Conference 310
1973 Chrysler Electrical Circuit Troubleshooting Reference, Master Technician's Service Conference 311
1967 Fuse Failures that are Tricky

Another situation to be careful with is when the switch is located in the ground wire. This is much earlier the 1972 but would still apply to some circuits.
Automotive Electricity (Session 118) Dome Light Switches
 
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No problem. Use the time to study up and make yourself some schematics of the systems you're having trouble with.

Here's some examples of schematics for a pre70 A-body. A car with steering column switch will have another connector, and colors and other things sometimes differ. Thats why the factory manual for your year is always the best starting point.

Main Power Feed Circuit.
(this one does not have the full charging circuit shown, its just power feeds)
upload_2019-1-8_9-9-41-png.png


Same car; Starting, Run, and Charging Circuits.
upload_2019-1-15_15-28-0.png


That started from this: Highlighting circuits of interest, then erasing the others.
upload_2019-1-15_15-29-42.png


Even after erasing, its easier to understand by redrawing or rearranging:
 
Mattax said:
No problem. Use the time to study up and make yourself some schematics of the systems you're having trouble with.

Here's some examples of schematics for a pre70 A-body. A car with steering column switch will have another connector, and colors and other things sometimes differ. Thats why the factory manual for your year is always the best starting point.

Main Power Feed Circuit.
(this one does not have the full charging circuit shown, its just power feeds)
View attachment 1715276112

Same car; Starting, Run, and Charging Circuits.
View attachment 1715276109

That started from this: Highlighting circuits of interest, then erasing the others.
View attachment 1715276110

Even after erasing, its easier to understand by redrawing or rearranging:
Click to expand...


Awesome thank you!

Question in regards to the Dome light and reading up on the materials you provided.

If I remove the wires from the door jamb switches.

Will that keep the lights on?
 
plumkrazee70 said:
Follow the wire from the starter solenoid back into the cabin.

Mine had melted to the positive ammeter wire, thus providing the 12 volts needed to turn the car over. Pretty easy to find if you know what your looking for.
Click to expand...

Say it ain't so
 
Leave it like that. It's cool and it's an anti theft device.
 
Mattax said:
Gary: Are you trying to solve your problem or Manny's (the OP)?
Be easier to do these one at a time - even seperate threads would be good.
Its almost a given one of Manny's headlight wires is contacting the start wire to the relay, especially if it only happens when the headlight switch causes the starter to turn when the headlights are on. If it happens when parking lights are on, then its a wire in that circuit (or instrument illumination).

Do yourself a favor and download the Dodge Service manual for your year. Then you'll have the best reference for colors etc. It still may have mistakes but less than the non-factory diagrams like those on mymopar.

For your problems with the signal and marker lamps take a look at the guidance from Tech. Using the FSM wiring diagrams, make a schematic - it may be the same as one of those shown in the Master Tech booklets, but it may be a little different.

1973 Chrysler Electrical System, Master Technician's Service Conference 310
1973 Chrysler Electrical Circuit Troubleshooting Reference, Master Technician's Service Conference 311
1967 Fuse Failures that are Tricky

Another situation to be careful with is when the switch is located in the ground wire. This is much earlier the 1972 but would still apply to some circuits.
Automotive Electricity (Session 118) Dome Light Switches
Click to expand...
His
 
Garys72Duster said:
Sorry Manny, just having some fun. I actually bought my green Dart in LA (Agoura Hills) back in October. Driving it back to Denver, the voltmeter kept jumping around, 14 to 16 volts. Found out the owner had by passed the amp gauge, but didn't tighten the nut holding the 2 wires together, that had previously went thru the amp gauge. So the entire elec system was getting fluctuating voltage! I finally ran a wire off a relay (12 volts positive) to the ignition side of the voltage regulator, and that helped alot. Then I found the loose connection where the PO had by passed the amp gauge. Tightened that up, now it charges a steady 15.5 volts! Not long after that, the turn signal problem cropped up. I'm just going to live with that for now. I would start with bypassing the amp gauge, and putting in a voltmeter. Alot of problems start there. Oh yea, the alternator went out on the way back to Denver too! Whats up with theses green cars? Mines only 49 years old! Ha!
Click to expand...
15.5 is too high. You have some weak grounds or excessive resistance somewhere. (usually the bulkhead connectors)
 
Yea the bulkhead connector is often a problem. As far as Mannys car goes, you can prob unhook the wires going to the dome light at the door switch. Doubt if that will solve much, other than keeping your fuse from blowing. But I'm always int in experimenting. That's how you learn. Start by tracing the yellow wire back from the starter relay, and see where it is intersecting the headlites on switch. Or more specifically, the wire that feeds 12 V to the headlites, when the lites are turned on. I'm sure you will find a wire crossed, or something that is shooting 12 V to the starter relay.
 
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Manny Valencia said:
If I remove the wires from the door jamb switches.

Will that keep the lights on?
Click to expand...
I think Gary pretty much covered it.
But let me ask; Do you understand this diagram?
upload_2019-1-15_18-6-32.png


This what you're asking.
upload_2019-1-15_18-13-41.png


If you don't understand, then say so. Its really important to understand the basics to trouble shoot.
 
Mattax said:
I think Gary pretty much covered it.
But let me ask; Do you understand this diagram?
View attachment 1715276150

This what you're asking.
View attachment 1715276153

If you don't understand, then say so. Its really important to understand the basics to trouble shoot.
Click to expand...

I understand when the door opens it triggers the dome light to come on due to the switch making ground contact.

There are no other on/off switches that control the dome lights.


I just want to make sure that when I unplug the black and yellow wires from the door jambs.

This will keep the lights off so I would need to install a switch to be able to turn on and off the dome lights.

Since the dome light fuse kept burning, I put a switch connecting the fuse terminals so I am able to turn the dome lights on and off without a fuse
 
A fuse is NOT a switch. It is supposed to be circuit protection. You better get a fire extinguisher.
There are lots of skills and talents beyond me, that I leave for someone that knows what they are doing. BUT you need to know electrical basics. A must, or unplug it and leave it for someone that understands it.
 
Manny Valencia said:
I understand when the door opens it triggers the dome light to come on due to the switch making ground contact.

There are no other on/off switches that control the dome lights.


I just want to make sure that when I unplug the black and yellow wires from the door jambs.

This will keep the lights off so I would need to install a switch to be able to turn on and off the dome lights.

Since the dome light fuse kept burning, I put a switch connecting the fuse terminals so I am able to turn the dome lights on and off without a fuse
Click to expand...
Manny that's not a good idea. Because now whatever short is causing the fuse to blow, will continue to conduct battery current to ground, without anything to stop it. If the fuse is a 15 amp, and 30 amps go thru it, it will blow and interrupt the circuit. But if you eliminate the fuse, then the current (say 30 amps) will continue to flow, and the wires will heat up, melt the insulation, and create more shorts to ground. Then you have real problems. If you start to smell burning plastic when the dome light is on, turn the switch off!
 
Manny Valencia said:
I understand when the door opens it triggers the dome light to come on due to the switch making ground contact.
Click to expand...
That's correct.
Manny Valencia said:
There are no other on/off switches that control the dome lights
Click to expand...
Incorrect.
Manny Valencia said:
I just want to make sure that when I unplug the black and yellow wires from the door jambs.

This will keep the lights off so I would need to install a switch to be able to turn on and off the dome lights.
Click to expand...
If any one of these switch wires touches ground, the done light circuit will be complete.
Since the dome light fuse kept burning, I put a switch connecting the fuse terminals so I am able to turn the dome lights on and off without a fuse
Click to expand...
This is dangerous.
 
Gary. You definately want to find where the resistance is. That's bad for the battery and bad for lights.
toolmanmike said:
15.5 is too high.
Click to expand...
Garys72Duster said:
Yea the bulkhead connector is often a problem.
Click to expand...
On my '67 I've found the ignition wire from the bulkhead to the regulator had a 1/2 Volt drop. The terminal crimp at the ballast resistor connection wasn't good. so you never know. Measure ffor that voltage drop back backprobing while running and take of it. :elmer:
 
Like in Young Frankenstein, she removes the candlestick, and he blocks the rotating bookcase with his body, and gets smashed up a little. Then he says DON'T PUT THE CANDLESTICK BACK, just shove on the opposite side of the bookcase. This frees him up, as he came close to disaster. In other words, this may be a job for someone who really knows what's going on. By the way, on my GREEN 1970 Dart, you can rotate the headlite switch counter clockwise, and the dome light comes on. Yours should be the same. This may be a clue. Headlite switch is giving problems, or wired up wrong. Yours is a 1972? Is that right?
 
Manny Valencia said:
I understand when the door opens it triggers the dome light to come on due to the switch making ground contact.
Click to expand...
Do you now understand how power can be at lamp, and it doesn't light up?
Like you observed here
Manny Valencia said:
These issues began when I was investigating why my brake lights were not working, they all illuminated, but wouldn't signal me using my brake.

Then all of a sudden my rear taillight stopped working but they were receiving power, bulbs aren't burnt.

That is when I realized when I turned on my headlights my passenger fender mounted turn signal was on and my driver side grille turn signal, was on with constant power but not the other turn signals. Turn signals should only get power when using the turn signal lever on the column.
Click to expand...
it might be switched on th eground side or it could be a bad ground wire connection causing the open circuit.
 
Garys72Duster said:
you can rotate the headlite switch counter clockwise, and the dome light comes on. Yours should be the same.
Click to expand...
Yes. That will be the same.
There may also be connections to map light switch or trunk light if the car has those options. I don't think so, but would want to check before saying definately one way or the other.
 
Just noticed on your original video, there are some gauges wired in under the dash. Someone has been working in there, and probably has crosswired some connections. Or hooked wires up to the wrong spot.
 
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