Turn signals not working, blowing fuse

[hotrod swinger]

I’d like to try to isolate the problem by disconnecting the radio terminal and checking the wires.

Radio connector, page 8-168 of the 73 Dodge Dart section from FSM, MyMopar

What are the orange wires and what do I do with those?

 

[hotrod swinger]

I have my gauge cluster out. I tried disconnecting all of the connectors on the circuit and the only connector that eliminated the ground was the bulkhead connector for reverse lights and wiper motor.

Tonight everything is working again so I must have bumped or disturbed the problem area.

Nothing obvious, no obvious burnt or loose wires or connectors. I’m going to leave everything apart and continue to look for the problem and post when/if I find it.

I was hoping it would be something obvious.

I’m seriously considering removing the entire dash harness from the vehicle and examining it on the bench, just looks like a daunting task.

 

[67Dart273]

I’d like to try to isolate the problem by disconnecting the radio terminal and checking the wires.



What are the orange wires and what do I do with those?

Orange are typically all the dash dimmer controlled lighting. That is a low power circuit and unlikely to be the problem. That circuit is a "trick." There are two feeds to the light switch. Headlights ONLY are powered by unfused power coming from the black ammeter wire "welded splice." There's a breaker in the light switch

The dash dimmer and tail/ park circuit is powered from a separate fuse. That power goes through the dash dimmer and back to the fuse box (on tan) to the small INST fuse, at one end of the fuse box. That fuse is only powered when the lights are at least on park, when the tail light circuit is working (fuse) a nd when the dimmer control is turned "some" to the left.

 

[67Dart273]

Getting that harness out is not terrible if you are in decent physical shape. You have to release the clips holding the bulkhead connector in place, and snake the pigtail out that goes down into the left kickpanel area. Carefully snake out the far end, the glovebox light, the heater controls, the radio, cigarette lighter connector, etc, and work your way back, the fuse panel, the brake light switch, and turn signal and key switch and headlight connectors,

Frankly at this point it might be a good idea.

BEFORE you do that (if you have not) I would untape from the ammeter down to at least near the bulkhead connector, and to the fuse panel and key switch. You can put temp ties along the way to keep stuff organized. These last areas are the ones with high current and no or poor fuse protection.

Other than that as we have tried to outline, follow the path of the daisy chain wires that go from the fuse that is blowing

If you know FOR CERTAIN which fuse, follow the wire, untape as you go, temporary tie as you go.

LOOK as you go, for hard harness wrap that might indicate "heat," or meltage, and of course shriveled and damaged wrap and wiring.

ALSO remember that this problem may not have started with that circuit. HOT insulation, damaged, melted, may have damaged the wire that is now giving trouble

 

[hotrod swinger]

Although I am able to twist and contort to work under the dash, I think I’m going to investigate a bit further with the harness in the vehicle.

Now that everything is working again I might start everything up and do some wiggle testing tomorrow to see if I can replicate the problem.

I will unwrap the harness as well and look for problems as suggested.

Thanks for everything.

 

[67Dart273]

You are really getting, I think, to the point that you need to sit down and look expressly at the wires that come from the fuse that was blowing. Make some notes where they go and what they are. As I tried to ouline earlier, as did Mattox, how they are daisy chained. Following "that path" surely will eventually lead you to it.

We are lucky these girls are not Imperials or Furies or something LOL Lots of options and extra "stuff" in those girls!!!

 

[hotrod swinger]

It’s too bad the FSM diagrams aren’t correct. They really threw me off with the brake lamps being listed as part of #3.

 

[67Dart273]

I don't know that the actual diagrams are wrong. I think the main AFU was that chart listing the fuses.

If you have a printer I would print out..........

The figure before the diagrams start which pictures the bulkead connector and it's circuits
The diagram pages, this is so you can hold them side by side and more easily follow conductors
The pertinant pages on past the diagrams which show the connector diagrams.

Also somewhere in the beginning, before the wiring diagrams, should be a chart showing what the various wire alpha codes mean, like J for ignition, etc.

I do not generally like the 73/ later style of diagrams, much harder to follow, sometimes. The newer stuff in the late 90's and later is much worse. I have an 04 GMC and detest trying to follow the shop manuals.

 

[Mattax]

Not much to add/

I should say with that connector removed I have no turn signals or blower.

That bulkhead connector has the wiper harness, the two reverse light wires and a third wire. What is the third wire?

See what matches on your car to what is in the book.

Seems like you did that.

I tried disconnecting all of the connectors on the circuit and the only connector that eliminated the ground was the bulkhead connector for reverse lights and wiper motor.

IF the problem was solved by disconnecting the connector on the engine side of the firewall;
Then that's where it makes the most sense to concentrate next.
Since nothing looked obvious you could take your meter to the wire terminal and confirm the short is in that cable.*
You can also check the wire terminal returning from the reverse switch. The switch should be isolated from ground. But that wire eventually goes to the reverse lights themselves. If the bulbs are good, they are in contact with ground. In other words the ohmmeter isn't going to give you a clear answer on the wire going to the bulbs.

Tonight everything is working again so I must have bumped or disturbed the problem area.

Including or not including the circuits on the bulkhead connector?

The circuit diagram in the FSM is correct as far as we can tell.
If you find something that differs, then note it.
Everyone makes mistakes. The mistake we found was in the fuse listing, and the wiring diagram confirmed that including the brake lights on a key switched fuse was wrong.

Now think about that reverse light switch. Is this an automatic? If so, what else is on that switch?
and no I'm not saying its inside the switch. I'm just saying to think about the possibilities based on what the switch does.

* You can also remove the individual terminals from that bulkhead connector.
remove the foam seal.

Then squeeze the barb and when its clear it will slide out pretty easily.

If the foam seal is deteriorated like in this photo, DMT has new ones.

 

[hotrod swinger]

The car is an automatic.

 

[hotrod swinger]

IF the problem was solved by disconnecting the connector on the engine side of the firewall;
Then that's where it makes the most sense to concentrate next.

Just so I’m clear, you’re saying to remove the bulkhead connector and check each of those terminals for continuity?

 

[Mattax]

Just so I’m clear, you’re saying to remove the bulkhead connector and check each of those terminals for continuity?

You tell us.
What are you trying learn with these continuity measurements?

I'm still not sure what you measured when you got a full ohm on the meter.
However you posted that removing the bulkhead solved the short. OK, so why did you stop there?
Was this at the same time as disconnecting the radio? which I thought you had already disconnected.

It seems to me that you're not sure of the reason we probe for continuity to ground.
Likewise why we have suggested disconnecting things.

So you tell us.
Assuming removing the bulkead connector solved the problem, what might be learned by checking the terminals?
Also, if you know, tell us what else the reverse light switch does?

 

[67Dart273]

Bear in mind that disconnecting the bulkhead may have FALSELY removed the "problem" because if you were on the wrong track, and disconnected the bulkhead, it may have broken a circuit that "normally" would have shown that particular reading.

Remember: Ohm's law. It is difficult to measure low ohms readings. That is why I try to go as far as I can with voltage readings.
I=E/R. This means as an example, that a circuit showing 1 ohm only draws 12.6A or whatever battery voltage is. Not only that, but bulbs become much lower in resistance when unpowered/ cold filaments. I have no idea, offhand, "let's say" what the parking/ tail lamp/ marker circuit might read for continuity when unpowered. It will not be very much. Ditto for headlights

Another example. Reverse light circuit, a pair of 1156 lamps. They are rated at 27w, so 2x is 54 watts. P=IE so 54= I x 12.6. That's about 4A

R= Esquared/ P so R + 12.6 squaared / 54 is about 3 ohms. Again that is operating conditions so that reading will be less when the bulbs are unpowered. You can measure a few bulbs to get an idea. 1157 stop/ tail lamps are same wattage on the turn/ stop filament, 54 watts

 

[hotrod swinger]

That wasn’t a full ohm on the meter, that is what my meter shows when there is no continuity.

I didn’t disconnect the radio, it was never connected.

I don’t think the reverse light switch does anything else. As far as I know, I don’t have a reverse indicator light.

 

[hotrod swinger]

I also remain conscious of the fact that my under dash harness was melted together last year and while I did my best at the time to pull all of those wires apart and repair them I may not have caught everything or made great connections.

I am an amateur, just learning all of this.

This morning everything is connected and working. I tried to wiggle all of the connections and I couldn’t blow the fuse. I have left the gauge cluster and kick panels off so I can continue my search.

I think my next step will be unwrapping the harness behind the gauge cluster in certain areas.

Ideally, I would like to pull the entire harness and examine it on a bench.

To recap, I disconnected my ammeter and added a jump wire between the alternator and battery after finding those melted wires last year, also did the headlight relay kit, so at least I have reduced some of the current in the cabin.

 

[hotrod swinger]

I should also add when I say “everything is working” that is without the gauge cluster attached. None of my gauges or warning lights work, which could very well be connected to this problem.

I want to find this short first, then focus on the gauge cluster second.

 

[67Dart273]

Keep at it. Sometimes perseverance is as effective as any other method. My example about the back up lamps was simply an example to illustrate a normal load. Again, low ohm readings are to be taken with a "grain of salt." The melted area would surely be of concern

 

[RedFish]

I should also add when I say “everything is working” that is without the gauge cluster attached. None of my gauges or warning lights work, which could very well be connected to this problem.
I want to find this short first, then focus on the gauge cluster second.

The instrument panel doesn't have a ground wire. so, while it dangles from its harness connectors, the only features that will function are brake warning lamp and oil warning lamp. Those get their ground at remote switches.

 

[hotrod swinger]

The instrument panel doesn't have a ground wire. so, while it dangles from its harness connectors, the only features that will function are brake warning lamp and oil warning lamp. Those get their ground at remote switches.

It isn’t connected at the moment, I meant that the gauges have not been working for a long time.

 

[hotrod swinger]

Just curious, if I had a reverse gear indicator lamp where would I find that in the harness?

 

[Mike69cuda]

I don’t know if you have tried this, but one thing I have done in the past is to put a tail light bulb in place of the fuse that is blowing. If you have a friend watch the bulb, you can wiggle wires around till the bulb lights up.

The bulb should be out, or dim with nothing on. It should be full brightness when you get a short. The bulb will limit the current so nothing burns up.

I used to have a burned out fuse with wires soldered on each end to hook the bulb to.

This is kind of a crude method, but sometimes you get lucky with it.

 

[hotrod swinger]

I am dutifully following the wiring diagrams as advised.

When I see CE 2(B) and CE 2(A), the bulkhead connector, which one is B and which one is A?

 

[Mattax]

I didn’t disconnect the radio, it was never connected.

Ok. It seemed like you had because you asked about it in post 51.

So as far as I (we) know, disconnecting the bulkhead was the first success in preventing the fuse from blowing.
Of course that might be a misunderstanding on my part.

I don’t think the reverse light switch does anything else. As far as I know, I don’t have a reverse indicator light.

The reverse light switch turns on the backup lights.
Your car is an automatic so there should not be reverse indicator inside. Might ther be a wire for that option? yes, might be.
The reason I asked you about the switch is this:
The reverse light switch and the neutral safety switch are combined into one unit.
The neutral safety switch works by grounding a wire coming from the starter relay whenever the gearshift is in P or N.

Think about that. Three wires connect the the transmission neutral safety/reverse light switch. One of those wires is grounded whenever the transmission is park or neutral. My understanding was the fuse did not open once you removed the connector with the reverse wire going to that switch.

I am an amateur, just learning all of this.

That's OK. I just thought its time we help you think this through rather than walk you through.

 

[Mattax]

I am dutifully following the wiring diagrams as advised.

When I see CE 2(B) and CE 2(A), the bulkhead connector, which one is B and which one is A?

Go to the end of the section and there is are illustrations of all of the connectors.

Looks like its page 164

Use the bumpouts on the connectors to confirm orientation of the drawing compared to what you see on the car. I suspect the artist didn't know how it will be oriented in the car.

Also they usually only provide an engine side or a passenger compartment view. It was up to the tech to reverse it when needed.

CE = Connectors in Engine bay
B1 probably means Backup 1 18 BK is 18 gage Black, a fairly small wire.

 

[hotrod swinger]

Ok. It seemed like you had because you asked about it in post 51.

Yes, I was going to follow advice and disassemble the connector to try and isolate the problem.