Mopar_Parr
Active Member
yes
67 Dart Conv. - No Tail Lights, Park Lights, Flashers
- Thread starter Mopar_Parr
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This may look complicated because it has the connections and both interior lights shown.
But its not and maybe we can clean it up later.
We need to look at how closing and opening a door could effect power at L8
But its not and maybe we can clean it up later.
We need to look at how closing and opening a door could effect power at L8
Door open, current should flow
Brake on, current should flow
If the ammeter isn't indicating flow under those conditions then one possibility is a weak fuse.
When electrons flow through resistance, voltage drops. If there is real high resistance at the fuse then just a tiny bit of current will make it through. What does get through has lost of its energy. They return to the battery just like they return through a grounds - at very low ernergy levels.
Mopar_Parr
Active Member
Not sure how to check the ammeter for flow. Is it simply looking at the gauge with the needle right of center towards the charge side? Or hook up a voltmeter to read the amps?
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The other way. The needle should move a little to the left of center toward discharge.
The ammeter shows
D for battery discharge.
C for battery charging.
So why is the gage labeled 'Alt' when it really shows current to or from the battery?
If the battery is discharging when driving, then the engine is running on battery and something is wrong with the alternator or alternator circuit. So in a round about way it informs us about the alternator operation.
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I'm more convinced than last night that the issuecould be the fuse or in a fusebox connection.
With anything turned on in the circuits coming off the fuse, voltage drops to zero.
Here's a way to check for resistance in the fuse.
Clip or hold a voltmeter probe onto the fuseholders. Red probe on the supply side and black probe on the downstream side.
Then turn something on that is connected to that fuse. It could be the courtesy lights, the brake lights, or parking lights. it doesn't matter.
If current tries to flow through and there is high resistance, it will show on the meter as a voltage drop.
In this case we may see the meter go from zero to 11 or 12 Volts.
if its not in the fuse itself, then check the backside - maybe its in one of the connectors.
We know the high resistance is not in the wiring leading to the L1 wire because the headlights work and you've used that to jumper the branches of circuits.
With anything turned on in the circuits coming off the fuse, voltage drops to zero.
Here's a way to check for resistance in the fuse.
Clip or hold a voltmeter probe onto the fuseholders. Red probe on the supply side and black probe on the downstream side.
Then turn something on that is connected to that fuse. It could be the courtesy lights, the brake lights, or parking lights. it doesn't matter.
If current tries to flow through and there is high resistance, it will show on the meter as a voltage drop.
In this case we may see the meter go from zero to 11 or 12 Volts.
if its not in the fuse itself, then check the backside - maybe its in one of the connectors.
We know the high resistance is not in the wiring leading to the L1 wire because the headlights work and you've used that to jumper the branches of circuits.
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Some might say just swap fuses with the cigar lighter and see what happens.
If doing that, leave the column disconnected. There's a chance the horn blowing and the stop light fuse blowing could be from the same cause and it might be in the column. Putting a new fuse may just result in another blown fuse.
Some might say just swap fuses with the cigar lighter and see what happens.
If doing that, leave the column disconnected. There's a chance the horn blowing and the stop light fuse blowing could be from the same cause and it might be in the column. Putting a new fuse may just result in another blown fuse.
For those following along, this is how its supposed to work.
If its 12.5 volts at the power source, when the switch is turned on it should be 12.5 volts through the entire line to the bulbs.
In a perfect ground, it will be zero volts from the ground all the way back to the power source.
The voltage difference across the fuse will be zero.
In the scenario below, there is a big voltage drop when the switch is turned on. Its after the main splice because L1 and J1 work fine.
Therefore most likely related to the shared fused.
Thats why we are measuring for voltage drop across the fuse.
Use the same technique to find resistance that is large enough to cause problems but too small to show up on a typical multimeter.
Test for drops along the flow path when current is flowing.
Change in Voltage = Current x Resistance.
If its 12.5 volts at the power source, when the switch is turned on it should be 12.5 volts through the entire line to the bulbs.
In a perfect ground, it will be zero volts from the ground all the way back to the power source.
The voltage difference across the fuse will be zero.
In the scenario below, there is a big voltage drop when the switch is turned on. Its after the main splice because L1 and J1 work fine.
Therefore most likely related to the shared fused.
Thats why we are measuring for voltage drop across the fuse.
Use the same technique to find resistance that is large enough to cause problems but too small to show up on a typical multimeter.
Test for drops along the flow path when current is flowing.
Change in Voltage = Current x Resistance.
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Mopar_Parr
Active Member
Well Sir, I am extremely embarresed to report that it was corrosion fuse block. You nailed it. I had previously cleaned the bottom fuse side of L8. L8 was extremely corroded (rusted) on the top side of the fuse block there. As soon as I got it cleaned up L8 became hot continously even with the door open. Everything parking, tail, and dome lights are working properly.
Thanks Matt, I greatly appreciate the effort that you have put into this in order to find a solution.
Ha! There's some threads you can look for sharing cleaning methods of terminals and the same can apply at the fuse clips too.
These things can be difficult sometimes to figure out.
I had major frustration on my Heep I mean Jeep with terminals that were loose. They look OK, then put the (Ford) connector on the coil or the one to into the (GM) alternator. Randlomly the engine would die and come back to life. Similarly alternator would stop working. In both cases it was terminals not holding in the plastic connector and so they would touch the male terminal but not slide onto it.
These things can be difficult sometimes to figure out.
I had major frustration on my Heep I mean Jeep with terminals that were loose. They look OK, then put the (Ford) connector on the coil or the one to into the (GM) alternator. Randlomly the engine would die and come back to life. Similarly alternator would stop working. In both cases it was terminals not holding in the plastic connector and so they would touch the male terminal but not slide onto it.
What's left? Horn?
While its disconnected, use the meter to see if the H3 wire is grounding without the horn button being depressed.
That will show whether or not the horn blowing is due to that wire grounding when it shouldn't.
While its disconnected, use the meter to see if the H3 wire is grounding without the horn button being depressed.
That will show whether or not the horn blowing is due to that wire grounding when it shouldn't.
Mopar_Parr
Active Member
Horn is next, I will dig into it this weekend. I’ll
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