Inline fuse continues to blow fuses

[magg383]

This might help, used for my Gen3 swap, but shows voltages for ignition switch.
Ignore text at bottom, that's for Gen3 wiring.

https://postimages.org/][/url]

Thats a nice easy to read chart! That should be posted somewhere where everyone can see it.

My readings are all correct w/ the exception of ACC chart reading.

I have no continuity w/ any of the other colors.
Chart says there should be w/ ACC (BLK)

Any ideas on what this would suggest? Thanks!!

 

[72RoadRunnerGTX]

Are you sure you are in ACC position on the switch, it’s counter clock-wise from the lock position for ACC only. Should have continuity between the black and red wires. Agreed, that chart is wrong in regards to Ign 1 and Ign 2, Ign1 is dark blue, Ign 2 is brown technically.

 

[magg383]

Are you sure you are in ACC position on the switch, it’s counter clock-wise from the lock position for ACC only. Should have continuity between the black and red wires. Agreed, that chart is wrong in regards to Ign 1 and Ign 2, Ign1 is dark blue, Ign 2 is brown technically.

Thanks for the reminder! After rechecking in the ACC position in the counterclockwise position, I DO have continuity between BLK and RED wires.

I think this ign. switch test now eliminates a bad switch.
Looks like my next step is I'm going to have to start unwrapping some electrical tape like Challenger RTA mentioned unless anyone knows of any other electrical tests that I can perform. Thanks!

 

[Challenger RTA]

Unplug all bulkhead connectors and the under column plugs turn signal too. At the column check all the connections to the battery wire and the Acc wire. Let us know what you get. Most should read open. With the exception of thing like the turn signal and 4 way flasher and indicator bulbs. Check each one to ground also.

 

[magg383]

Unplug all bulkhead connectors and the under column plugs turn signal too. At the column check all the contentions to the battery wire and the Acc wire. Let us know what you get. Most should read open. With the exception of thing like the turn signal and 4 way flasher and indicator bulbs. Check each one to ground also.

I'll be out of town until Mon. When I get back:

Should I be checking all the pins on the other end of the ign. switch for continuity then?
If so, besides the switch pins, where should I connect the other meter probe to?
If so, with ign. on or off? (I presume off)

Same questions while testing the bulkhead spades?
What does the other probe touch to? (The other side of bulkhead, where it plugs into?)

Are there other plugs under column also?
If so, what are they?
Thanks!

 

[Challenger RTA]

Ok you don't understand somethings. That's fine. That's what were here for.
As in #44 I'll put it an other way
What you are going to do. is connect the 1 lead of the meter to the under column plugs red battery and leave it there. Touch every pin in the connector. Then do the same for the black Acc wire. They all should read OL open line or no change on you meter, depends on you meter. No continuity. If you do read something let us know what it is. It could be the short or it can be completing a circuit.

 

[magg383]

I checked the other side of the ign. switch at the molex for continuity from red (batt) to the other pins. All 4 of the main pins show continuity. Of all the pins, the only one that shows no continuity is (E2-18 O) that goes to (key in buzzer) at fuse block. I won't be able to disconnect bulk heads because we drilled out holes in bulkheads for the alt. and battery and ran those wires straight through.

(Note) Continuity was checked w/ car battery disconnected. does this make a difference?

 

[Challenger RTA]

When you disconnect the bulkhead connector , you can't slide the wire through it?
If not you will have to disconnect every thing under the hood that is connected to it. Make sure you disconnect the battery. Then check all the wires in the Molex connector. Unplug the bulkhead connector that you can.

 

[magg383]

When you disconnect the bulkhead connector , you can't slide the wire through it?
If not you will have to disconnect every thing under the hood. Make sure you disconnect the battery. Then check all the wires in the Molex connector. Unplug the bulkhead connector that you can.

Did you see post #47? I checked all the wire pins at the molex with all the continuity results listed. Are those results correct?

Did you see the question about the battery disconnected also?

 

[Challenger RTA]

Your were checking the continuity ign sw correct? Depending on the position of the sw. If so yes.

 

[72RoadRunnerGTX]

Did you see post #47? I checked all the wire pins at the molex with all the continuity results listed. Are those results correct?

Did you see the question about the battery disconnected also?

Continuity tests do not work well with that Molex application, need to do voltage drop test across those pins while under load, current flowing.

 

[Challenger RTA]

When you get things disconnected as described above. Check the molex connector down steam the column. In theory they all should read open OL. If you find something let us know. You might be completing a circuit.

Continuity tests do not work well with that Molex application, need to do voltage drop test across those pins while under load, current flowing.

Thanks,That is understood. But he doesn't have a Megger. Working with what he has.

 

[Chryco Psycho]

What maybe you don't understand is a fusable link is a slow blow fuse , it can get hot before failing outright , a fuse is a quick blow .
Everything might be fine using a proper fusable link instead of a fuse

 

[magg383]

Continuity tests do not work well with that Molex application, need to do voltage drop test across those pins while under load, current flowing.

So, I should connect my battery back up and w/ the Molex disconnected, check ea. Molex pin w/ the black probe while having the voltmeters red probe on the batteries red pin (J1-12R)?

If so, what numbers (drop) should I be looking for on ea. pin with my voltmeter? I'm guessing any one that has a significant drop vs. others? Thanks

 

[magg383]

What maybe you don't understand is a fusable link is a slow blow fuse , it can get hot before failing outright , a fuse is a quick blow .
Everything might be fine using a proper fusable link instead of a fuse

Thanks for the input. I can try to put a 14-gauge fusible link back in. I just worry that if there is actually a short somewhere after putting a fusible link in, how will I know? I would hate to create more electrical issues if there is a short somewhere. Your thoughts on that?
Also, the 30 Amp inline fuse holder in there now is 12-gauge vs the recommended 14. Would that make much of a difference?

 

[Chryco Psycho]

Take the fuses out of the fuse block & test for load or short with a multimeter , put 1 fuse in at a time see what changes , check temp of the link with a laser temp sensor .

 

[Challenger RTA]

When you disconnect the bulkhead connector , you can't slide the wire through it?
If not you will have to disconnect every thing under the hood that is connected to it. Make sure you disconnect the battery. Then check all the wires in the Molex connector. Unplug the bulkhead connector that you can.

When you get things disconnected as described above. Check the molex connector down steam the column. In theory they all should read open OL. If you find something let us know. You might be completing a circuit.

Keep the molex connector under the column disconnected. Disconnect all bulkhead connector that can be disconnected.
The bulkhead connectors that can't be disconnected, follow wiring and disconnect form what it is connected to.Be sure to disconnect the battery.

This exercises is to determine what wire or part of the harness the short could be in. connect test lead to the red and the other test lead touch to every wire. As I said they should be open. If not you might be completing a circuit that is still connected or it is a short. If you find anything make note of it and let us know.

 

[magg383]

Keep the molex connector under the column disconnected. Disconnect all bulkhead connector that can be disconnected.
The bulkhead connectors that can't be disconnected, follow wiring and disconnect form what it is connected to.Be sure to disconnect the battery.

This exercises is to determine what wire or part of the harness the short could be in. connect test lead to the red and the other test lead touch to every wire. As I said they should be open. If not you might be completing a circuit that is still connected or it is a short. If you find anything make note of it and let us know.

So I should perform the same test as I did in post#47 with the exception of having all 3 bulkhead connectors disconnected?

 

[Challenger RTA]

So I should perform the same test as I did in post#47 with the exception of having all 3 bulkhead connectors disconnected?

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.

 

[Katfish]

Are you sure you are in ACC position on the switch, it’s counter clock-wise from the lock position for ACC only. Should have continuity between the black and red wires. Agreed, that chart is wrong in regards to Ign 1 and Ign 2, Ign1 is dark blue, Ign 2 is brown technically.

Interesting, taken directly from 70 FSM