Inline fuse continues to blow fuses

[Challenger RTA]

I'll just go a little ahead. If you test the dash wiring and no shorts. plug in one bulkhead connector and retest. One Ping only. ( Red October) Good movie. If you find no short unplug the one you tested and try another until all are tested.

 

[Challenger RTA]

Interesting, taken directly from 70 FSM

Are you in darken ship mode.The red lights are on. Blue looks green not purple at times. in red lights. No really I know what you are saying. Just trying to get him through this. A crap he is going to cut the wrong wire where all going to die!

 

[Challenger RTA]

Should have posted this sooner. To test the dash wiring test the plug on the left. To test the ign sw ,test the plug on the right side.

 

[72RoadRunnerGTX]

Interesting, taken directly from 70 FSM

While FSMs are the most complete and accurate source of technical information for these cars, they still contain some flaws and omissions. Some diagrams have that labeling reversed. Dark blue with a trace is in fact ignition 1, power in the run only position. Brown is ignition 2, the ballast resistor by-pass, power in the crank only position. In the 1970 FSM the diagram for the E-body Rallye cluster is incorrectly labeled while the diagram for the standard cluster is correct. Same switch is used on other platforms, a few diagrams for B-bodies also have them reversed.

'70 FSM e-body standard cluster;

'70 FSM E-body Rallye cluster;

 

[Challenger RTA]

While FSMs are the most complete and accurate source of technical information for these cars, they still contain some flaws and omissions.
Only in a perfect world! Right! With out looking The DBL * with white tracer changes to blue under the hood.

 

[Challenger RTA]

Here is a view of the harness unwrapped. You can see the DBL* run and the Brown start.

 

[magg383]

I'll just go a little ahead. If you test the dash wiring and no shorts. plug in one bulkhead connector and retest. One Ping only. ( Red October) Good movie. If you find no short unplug the one you tested and try another until all are tested.

Thanks for all your direction. Hopefully I can get a chance to get back in the garage this weekend and test the other side of the Molex.

 

[magg383]

Yes. The idea is to find where the short is. In the dash area with the bulkhead connectors disconnected. When the bulkhead connectors are plugged in then it's in the bulkhead plug wiring. So from doing from under the column it the same test area. don't be jumping around just yet.

OK, with all the bulkheads disconnected, checking the other side of the Molex (non ign. side)

There IS continuity between the red (J1-12R) and:
Q2-12BL
J2A-12DBL*
Also IS between the smaller wire connections of:
M16A-20BK
E2A-18 0/ E2-18 0

What do these check results suggest and what's next step?

 

[Challenger RTA]

There IS continuity between the
(J1-12R) Has the power feed from splice one, from battery and alt.
Q2-12BL Feeds the acc side of fuse box.
J2A-12DBL* Feeds ign.

In short they are shorted out tougher. They are separate circuits. same for the others.
M16A-20BK More than likely completing a circuit Key in buzzer.
E2A-18 0/ E2-18 0 More than likely completing a circuit cluster lights.
check them to ground also. If there not grounded then they melted together and may be a simple fix. I would guess a harness is about $600.


The pictures I posted are a common thing of being over heated or shorted. If shorted to ground the damage can be a disaster.
You have to open the harness to see what damage is and go from there.

Zip tied or tape the wires together to keep them some what organized. It will help when you go to make a repair.

 

[Challenger RTA]

72RoadRunnerGTX​

Showed a connector that can me used to replace the Molex connector. If you can do that. Wires not a total loss. Not hard and brittle. I did remove the amp gauge and wires. I Had an after thought after I redid my harness. That would be to have those wires outside the main harness. They are the higher current carrying wires or sometimes problematic.

 

[Challenger RTA]

This is the area where to look for the problem. Be sure to check the Black and red wires all the way the the amp gauge. This is splice one opened up. The splice is I think is never the problem. It's the heat generated by the load going though the splice wires.

 

[magg383]

OK, with all the bulkheads disconnected, checking the other side of the Molex (non ign. side)

There IS continuity between the red (J1-12R) and:
Q2-12BL
J2A-12DBL*
Also IS between the smaller wire connections of:
M16A-20BK
E2A-18 0/ E2-18 0

What do these check results suggest and what's next step?

I thought I would try to disconnect my quick disconnect battery switch that I have on my negative post on my battery to see if that made a difference.
Well, it did make a difference.

Now, there is NO continuity between the red (J1-12R) and
Q2-12BL and J2A-12DBL*
The only continuity is w/ those same 2 smaller wires.

What are your thoughts now?

 

[Challenger RTA]

The circuit is not being completed to ground is what it sound like. Hard to say with out hands on. Open the harness. Each wire is it own separate circuit. By chance Did you pull all the fuse first?
So if you switched your battery disconnect. The dash harness is not Isolated. Meaning you are testing something also other than the harness. Everything is not disconnected from it.

 

[magg383]

I thought I would try to disconnect my quick disconnect battery switch that I have on my negative post on my battery to see if that made a difference.
Well, it did make a difference.

Now, there is NO continuity between the red (J1-12R) and
Q2-12BL and J2A-12DBL*
The only continuity is w/ those same 2 smaller wires.

What are your thoughts now?

I connected the neg. cable again and still get the same results as above. Does that make any sense?

 

[Challenger RTA]

I would say the harness is shorted to to ground somewhere. But no it makes no sense. Something is still connected by ground or by damage. Fire wall block connector melted and grounded?

 

[Challenger RTA]

If you didn't take the fuse box of the firewall connector do so. It might be right there. As in #66

 

[magg383]

The circuit is not being completed to ground is what it sound like. Hard to say with out hands on. Open the harness. Each wire is it own separate circuit. By chance Did you pull all the fuse first?
So if you switched your battery disconnect. The dash harness is not Isolated. Meaning you are testing something also other than the harness. Everything is not disconnected from it.

I have all 4 bulkheads disconnected, so disconnecting the neg. cable couldn't have anything to do with it. I don't know why then that there was different readings after rechecking about 2 hrs. later.
Anyways, by having no continuity between the red and the other 4 main thick wires is what we wanted, correct?

 

[Challenger RTA]

When moving the wires or getting in and out and around. The wires can make and brake connection. Reading won't be constant.

 

[Challenger RTA]

Anyways, by having no continuity between the red and the other 4 main thick wires is what we wanted, correct?

YES

 

[magg383]

When moving the wires or getting in and out and around. The wires can make and brake contentions. Reading won't be constant.

When I checked the 2nd time, I didn't move any wires around? Should I purposely move some of the wires around that go from Molex to bulkhead area and see if I get continuity readings again?

Also, I did not remove any fuses. Was i suppose to?