Headlight Switch Cranks Engine??

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If it only happens with the headlight switch in the headlights on position, then yes you can eliminate the parking, marker and dash lights from being involved.
Follow the headlight power wire, and also the starter relay wire. There's not going to be many places where they would cross.
 
Replace the whole harness. Engine and dash. And bypass the bulkhead charging while you're at it (don't forget the fusible link)
 
I saw this happen once on a 1976 Ford Bronco. I was due to a broken engine to body ground. DC automotive wiring is crazy.
 
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I have a 1970 green Dart, and the left turn signal indicator comes on when the lights are turned on. Then outside the car, at the same time, the right turn signal is on! But when you're driving, the left signal flashes real slow while the right one works normally. I think this is due to the the fact that the cars were painted green from the factory. Different color cars like blue or red or yellow don't have these kind of problems. Get a different colored car, and the problem will go away. LOL
 
This is what I call spontaneous automobile malfunction. Similar to spontaneous human combustion, but without the devastating side effects.
 
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!
 
Does it continue to run after the headlites are turned off? Sounds like a couple wires crossed somewhere. Start at the starter relay. 1 Wire (the brown one?) actuates the starter relay when it receives 12 volts from the ignition switch. Then that relay sends full battery current to the starter. Somehow the headlite switch must be sending 12 volts to that wire, when you turn them on.
 
Garys72Duster said:
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!
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Great example of a good reason why most people shouldn't be doing this. Making changes that they don't really understand, and don't have the skills to execute well causes more problems than leaving it alone.
 
Manny Valencia said:
Sorry I mean I dont know know what that is specifically.

I have not installed the new under dash harness.
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You did understand. That's what Krazykuda was asking.
Answer: Problem occurred with old harness. Have not tested with new harness.
:)
 
Did this just start happening?
Was it working fine recently?
What work has been done prior to this?


Alan
 
Garys72Duster said:
Does it continue to run after the headlites are turned off? Sounds like a couple wires crossed somewhere. Start at the starter relay. 1 Wire (the brown one?) actuates the starter relay when it receives 12 volts from the ignition switch. Then that relay sends full battery current to the starter. Somehow the headlite switch must be sending 12 volts to that wire, when you turn them on.
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Yes

This never happened before.

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.
 
Garys72Duster said:
View attachment 1715275536 View attachment 1715275537 I have a 1970 green Dart, and the left turn signal indicator comes on when the lights are turned on. Then outside the car, at the same time, the right turn signal is on! But when you're driving, the left signal flashes real slow while the right one works normally. I think this is due to the the fact that the cars were painted green from the factory. Different color cars like blue or red or yellow don't have these kind of problems. Get a different colored car, and the problem will go away. LOL
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You might be onto something, Mines is factory green lol
 
All,

Another sign there might be a short (burned/fused wiring)

My trunk and Interior dome lights since I got the car always stayed on when I put a fused in then after 30 seconds, the fuse begins too cook itself.

I installed a switch to the fuse terminal at the box and it turns on and off the dome lights fine.

the dome lights are connected to door switches and relays.
 
Electrical challenges me, but by the sounds of it I would be going over all the wiring in this car. Keep battery disconnected and a fire extinguisher handy. Seriously.
Good luck. Lots of great advice so far.
 
Put in the new wiring harness, save the old one for the connectors and various colors of wire. I always keep each wire the same color if I do a splice. Solder the splices, if you are sure you have the right wires hooked up. I always check mine before soldering. This can be figured out. Don't be in a hurry. Think about it, ask the forum, and when you're sure you have the correct next step, then proceed. May need help from a local guy that knows these cars. Good luck!
 
Manny Valencia said:
My trunk and Interior dome lights since I got the car always stayed on when I put a fused in then after 30 seconds, the fuse begins too cook itself.
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Which means there is a short either between wires or to ground.
If its that bad, it can be found by following the wires and the method to use instead of looking for voltage drops would be checking continuity or resistance.
These are testing methods done with the battery disconnected.

The way to avoid going crazy looking at the wiring diagrams while working on the car is as follows:
Take the diagrams and trace or sketch just the circuit you are working on.
It may take two attempts but it will make everything much easier to follow.

There is problem with starting - draw the wires and connections for just that circuit.
Same with dome light.
Same with parking and turn signals. This can be one of the more difficult circuits, really two circuits. Having the markers on the fender makes just a little more confusing. Draw it out. Trace in real life, adjust your drawing as needed, put notes on it, whatever you need to keep track of what you've done and found.
 
Isolation, unplug the connectors at the bulkhead, remove wires at the starter relay, unplug front turn lights, unplug fender top lights, unplug headlights...

Personally I'd remove the under hood harnesses from the car to check them.

Check harness with meter.


Alan
 
Mattax said:
Not the issue. Stay focused/
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You're right, replacing the harness and bypassing the bulkhead aren't the issue with the OP's car.

Replacing the harness and bypassing the bulkhead will fix his issue and also eliminate what caused the issue.
 
jos51700 said:
Replacing the harness and bypassing the bulkhead will fix his issue and also eliminate what caused the issue.
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There is no evidence here of a poor connection at the bulkhead or at the ammeter. So it is illogical to conclude that such bypasses would eliminate the cause of the problem. The problems here are shorts - that is wire without insulation touching each other or incorrect connections. There may also be shorts to ground.
 
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